diff --git a/tests/README.md b/tests/README.md
index 50f7d41..0b937df 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -1,5 +1,81 @@
 # Discovery, installation and uninstallation verification
 
+## Executable test wrapper repair (2026-11-06)
+
+The first hosted run of the performance changes passed PowerShell, Git Bash
+and MSYS2 but failed both Bash versions on Linux/macOS and current Cygwin
+when creating the first installation's default link. Removing `ln` from the
+ordinary utility wrapper loop also removed its initial `chmod +x`; rewriting
+the failure-injection wrapper later did not set that permission. The harness
+now explicitly makes the completed `ln` wrapper executable before isolating
+PATH. Runtime code and test coverage are unchanged.
+
+The [hosted run](https://github.com/codejive/jvm/actions/runs/42131463064)
+completed its passing Windows jobs in 3:27 (PowerShell), 3:22 (Git Bash) and
+4:48 (MSYS2), including setup/checkout. Those results precede this permission
+repair; Linux, macOS and Cygwin still require a hosted rerun.
+
+Local Git Bash passed `bash tests/install.sh --defaults` (47 seconds), covering
+default creation, replacement, interrupted updates and removal rollback with
+simulated host layouts. Bash syntax checks and `git diff --check` passed.
+ShellCheck is unavailable. No local Unix/Cygwin runs, commit, push or hosted
+rerun were performed for the repair.
+
+## CI harness performance (2026-11-06)
+
+The PowerShell smoke harness now launches its ordinary script and CMD checks
+with `Diagnostics.Process`, drains stdout and stderr concurrently, and waits
+on the process directly. It preserves the PowerShell working directory,
+argument quoting, fresh-process isolation, stream assertions and exit-code
+checks. The three CMD paste checks retain file-backed `Start-Process` input.
+The suite reports elapsed time and the number of processes launched by the
+new helper. On the same local Windows machine, all 30 smoke groups passed in
+297.37 seconds before the change and 145.52 seconds afterwards (about 51%
+less elapsed time). These are local measurements, not hosted CI results.
+
+Discovery and installation link ordinary utilities into their isolated PATH
+instead of launching an extra Bash wrapper for every utility call. On MSYS,
+shortcut links avoid elevation and preserve the executable's DLL location.
+Installation retains scripts for failure injection and for utilities moved
+or replaced during capability tests; renaming MSYS shortcut links can lose
+their link identity. All 56 discovery groups passed locally in 52.97 seconds
+with the original wrappers and about 35 seconds with links. Runs overlapped
+other verification work, so these timings are indicative rather than a
+controlled benchmark.
+
+`tests/ci.sh` reports per-suite and total timings. Windows runs three installation
+partitions concurrently, each with independent temporary HOME/XDG roots,
+fixtures, logs and cleanup. A fourth worker runs discovery, home/env and the
+Bash installer suite in sequence while those partitions run. The harness waits
+for every partition and propagates any failure. Unix retains the full serial
+installation suite. The partition commands are also usable individually with
+the interpreter being tested:
+
+```sh
+bash tests/install.sh --contracts
+bash tests/install.sh --selection
+bash tests/install.sh --archives
+```
+
+Contracts cover metadata, ranges, manifests, inventory and uninstall selectors;
+selection covers defaults, flags, execution and configuration; archives cover
+the remaining installation, extraction and concurrent-publication checks.
+`bash tests/install.sh` and `bash tests/run.sh` retain their full serial behavior.
+Runtime scripts and product requirements are unchanged.
+
+The complete local Git Bash CI harness passed in 192.56 seconds (about 3:13),
+including all 56 discovery groups, the original 35 installation groups split
+12/9/14 across the partitions, home/env checks, all 19 Bash installer groups,
+native junction smoke and all 14 PowerShell installer groups. Comparing the
+installation group descriptions with the preceding hosted run found no missing
+or additional groups. Overlapping the other suites reduced the local harness
+from the first optimized schedule's 331.10 seconds (5:31). The PowerShell
+process helper also captured simultaneous 128 KiB stdout/stderr output and exit
+37 without blocking. Bash syntax, PowerShell parsing, LF endings and
+`git diff --check` passed. ShellCheck is unavailable. Linux, macOS, Bash 3.2,
+MSYS2 and Cygwin validation and same-runner hosted performance measurements
+remain pending; no commit, push or workflow dispatch was performed.
+
 ## Patch release preparation: 0.2.1 (2026-11-05)
 
 The runtime version constants, PowerShell HTTP User-Agent, version-output
diff --git a/tests/ci.sh b/tests/ci.sh
index 284146f..1507f50 100644
--- a/tests/ci.sh
+++ b/tests/ci.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Run with the interpreter being tested, never a compatibility-mode substitute.
 set -eu
+CI_STARTED=$SECONDS
 ROOT=$(cd "$(dirname "$0")/.." && pwd)
 case "${1:-}" in
     3.2)
@@ -14,7 +15,19 @@ esac
 printf 'Testing %s on %s\n' "$BASH_VERSION" "$(uname -a)"
 BASH_BIN=$BASH
 TEMP=$(mktemp -d "${TMPDIR:-/tmp}/jvm-ci.XXXXXXXX")
-trap 'rm -rf -- "$TEMP"' EXIT
+suite_pids=()
+cleanup() {
+    local pid
+    for pid in "${suite_pids[@]:-}"; do
+        [ -z "$pid" ] || { kill -TERM "$pid" 2>/dev/null || :; }
+    done
+    for pid in "${suite_pids[@]:-}"; do
+        [ -z "$pid" ] || { wait "$pid" 2>/dev/null || :; }
+    done
+    rm -rf -- "$TEMP"
+    printf 'TIMING: total: %ss\n' "$((SECONDS-CI_STARTED))"
+}
+trap cleanup EXIT
 trap 'exit 1' HUP INT TERM
 mkdir "$TEMP/bin"
 # Also cover env-bash shebangs and bare `bash` commands with this interpreter.
@@ -25,14 +38,45 @@ cd "$ROOT"
 "$BASH_BIN" -n ./jvm
 "$BASH_BIN" -n web/install.sh
 for script in tests/*.sh; do "$BASH_BIN" -n "$script"; done
-"$BASH_BIN" tests/run.sh
-"$BASH_BIN" tests/tool-installer.sh
+run_suite() {
+    local name=$1 started=$SECONDS status=0
+    shift
+    "$@" || status=$?
+    printf 'TIMING: %s: %ss (exit %s)\n' "$name" "$((SECONDS-started))" "$status"
+    return "$status"
+}
 case "$(uname -s)" in
     CYGWIN*|MSYS*|MINGW*)
-        "$BASH_BIN" tests/default-native-windows.sh
+        # Bound concurrency to three independent installation suites. Capture
+        # separate logs so output and failures cannot interleave or get lost.
+        suites=(contracts selection archives)
+        for suite in "${suites[@]}"; do
+            "$BASH_BIN" tests/install.sh "--$suite" > "$TEMP/$suite.log" 2>&1 &
+            suite_pids[${#suite_pids[@]}]=$!
+        done
+        # A fourth worker runs the remaining independent suites in sequence.
+        run_suite discovery "$BASH_BIN" tests/run.sh --discovery
+        run_suite home-env "$BASH_BIN" tests/home-env.sh
+        run_suite tool-installer "$BASH_BIN" tests/tool-installer.sh
+        status=0
+        for index in 0 1 2; do
+            wait "${suite_pids[$index]}" || status=1
+            suite_pids[$index]=
+            cat "$TEMP/${suites[$index]}.log"
+        done
+        [ "$status" -eq 0 ] || exit "$status" ;;
+    *)
+        run_suite discovery "$BASH_BIN" tests/run.sh --discovery
+        run_suite installation "$BASH_BIN" tests/install.sh
+        run_suite home-env "$BASH_BIN" tests/home-env.sh
+        run_suite tool-installer "$BASH_BIN" tests/tool-installer.sh ;;
+esac
+case "$(uname -s)" in
+    CYGWIN*|MSYS*|MINGW*)
+        run_suite native-junction "$BASH_BIN" tests/default-native-windows.sh
         # A restricted Cygwin PATH may contain System32 without its PowerShell
         # subdirectory. Include it for the suite's nested PowerShell/CMD calls.
         system_directory=$(cygpath -u -S)
         export PATH="$PATH:$system_directory/WindowsPowerShell/v1.0"
-        powershell.exe -NoProfile -ExecutionPolicy Bypass -File "$(cygpath -aw "$ROOT/tests/tool-installer.ps1")" ;;
+        run_suite powershell-installer powershell.exe -NoProfile -ExecutionPolicy Bypass -File "$(cygpath -aw "$ROOT/tests/tool-installer.ps1")" ;;
 esac
diff --git a/tests/install.sh b/tests/install.sh
index ba71018..7fbfd5d 100644
--- a/tests/install.sh
+++ b/tests/install.sh
@@ -8,6 +8,8 @@ TEMP=$(mktemp -d "${TMPDIR:-/tmp}/jvm-install-tests.XXXXXXXX") || exit 1
 # Fixtures and exact home/exec expectations share the manager's physical paths.
 # TMPDIR can name an alias such as /var on macOS or a Windows runner mount.
 TEMP=$(cd "$TEMP" && pwd -P) || exit 1
+SUITE_NAME=${1:-all}
+SUITE_STARTED=$SECONDS
 cleanup() {
     if [ -n "${TEST_PUBLISH_GATE:-}" ]; then
         : > "$TEST_PUBLISH_GATE/first.release"
@@ -22,7 +24,7 @@ cleanup() {
     done
     rm -rf -- "$TEMP"
 }
-trap cleanup EXIT
+trap 'status=$?; cleanup; printf "TIMING: installation %s: %ss (exit %s)\n" "$SUITE_NAME" "$((SECONDS-SUITE_STARTED))" "$status"; exit "$status"' EXIT
 trap 'exit 1' HUP INT TERM
 mkdir -p "$TEMP/project with spaces"
 cd "$TEMP/project with spaces" || exit 1
@@ -31,10 +33,18 @@ export XDG_CACHE_HOME="$TEMP/cache with spaces" XDG_CONFIG_HOME="$TEMP/config" X
 mkdir -p "$HOME" "$TEMP/bin"
 TOOLS=$TEMP/bin
 export MSYS=winsymlinks:nativestrict
-for tool in ln readlink mkdir mktemp rm rmdir sed awk cat cmp mv date cp sleep wc find tar gzip unzip sha256sum openssl; do
+for tool in readlink mkdir mktemp rmdir sed awk cat cmp date cp sleep wc find tar gzip unzip sha256sum openssl; do
     path=$(command -v "$tool") || continue
-    printf '#!%s\nexec "%s" "$@"\n' "$BASH_BIN" "$path" > "$TOOLS/$tool"
-    chmod +x "$TOOLS/$tool" || exit 1
+    case "$tool" in
+        readlink|awk|tar|unzip|sha256sum|openssl)
+            # These entries are moved/replaced in capability/failure tests.
+            # MSYS shortcut links lose their link identity when renamed.
+            printf '#!%s\nexec "%s" "$@"\n' "$BASH_BIN" "$path" > "$TOOLS/$tool"
+            chmod +x "$TOOLS/$tool" || exit 1 ;;
+        *)
+            # Avoid another Bash process for ordinary utility calls.
+            MSYS=winsymlinks ln -s "$path" "$TOOLS/$tool" || exit 1 ;;
+    esac
 done
 printf '#!%s\nprintf "%%s\\n" "$2"\n' "$BASH_BIN" > "$TOOLS/cygpath"
 printf '#!%s\ncat > /dev/null\nln -s "$JVM_TARGET" "$JVM_LINK"\n' "$BASH_BIN" > "$TOOLS/cmd.exe"
@@ -171,6 +181,7 @@ if [ -n "$TEST_DEFAULT_GATE" ] && [ "${3:-}" = "$XDG_DATA_HOME/jvm/jdks/$TEST_DE
 fi
 exec "$TEST_REAL_LN" "$@"
 EOF
+chmod +x "$TOOLS/ln" || exit 1
 export PATH=$TOOLS
 passed=0
 fail() { printf 'FAIL: %s\n' "$*" >&2; cat "$TEMP/err" >&2; exit 1; }
@@ -1396,6 +1407,18 @@ if [ "${1:-}" = --flags ]; then flag_alias_checks; exit 0; fi
 if [ "${1:-}" = --execution ]; then execution_checks; exit 0; fi
 if [ "${1:-}" = --defaults ]; then default_checks; exit 0; fi
 
+# Independent partitions of the full suite. Each process creates its own
+# fixtures/storage; the ordinary no-argument invocation still runs everything.
+case "${1:-}" in
+    --contracts)
+        ea_checks; type_checks; range_checks; java_major_checks
+        manifest_checks; inventory_checks; uninstall_checks
+        exit 0 ;;
+    --selection)
+        default_checks; flag_alias_checks; execution_checks; configuration_checks
+        exit 0 ;;
+esac
+
 if [ "${1:-}" != --publication ]; then
 run 0 list
 [ "$(< "$TEMP/out")" = "No JDKs are installed. Use 'install' to install one" ] || fail 'wrong empty inventory message'
@@ -1408,6 +1431,7 @@ done
 [ ! -e "$XDG_DATA_HOME" ] || fail 'empty listing created data storage'
 run 2 list ''; run 2 list ../21; run 2 list extra extra
 check 'empty offline inventory succeeds without creating storage; command usage'
+if [ "${1:-}" != --archives ]; then
 ea_checks
 type_checks
 range_checks
@@ -1416,6 +1440,7 @@ manifest_checks
 inventory_checks
 uninstall_checks
 default_checks
+fi
 
 index; row 21.0.2+9 vendor; run 0 install vendor-21; diagnostic '21.0.2+9-vendor'
 diagnostic 'Successfully installed 21.0.2+9-vendor'; diagnostic 'Installing 21.0.2+9-vendor...'
@@ -1715,9 +1740,11 @@ run 0 list
 contains '23+1-vendor'; contains '(invalid JDK)'
 check 'independent staging, race loser success, publication failure and preservation of prior installation/default'
 
+if [ "${1:-}" != --archives ]; then
 flag_alias_checks
 execution_checks
 configuration_checks
+fi
 
 saved_data=$XDG_DATA_HOME; XDG_DATA_HOME=relative
 index; row 24+1 vendor; run 0 install vendor-24
diff --git a/tests/powershell.ps1 b/tests/powershell.ps1
index b280580..40c8632 100644
--- a/tests/powershell.ps1
+++ b/tests/powershell.ps1
@@ -10,6 +10,8 @@ $scriptPath = Join-Path $repository 'jvm.ps1'
 $testRoot = Join-Path ([IO.Path]::GetTempPath()) ('jvm powershell ' + [guid]::NewGuid().ToString('N'))
 $oldEnvironment = @{}
 $script:passed = 0
+$script:processCount = 0
+$suiteTimer = [Diagnostics.Stopwatch]::StartNew()
 foreach ($name in @('HOME', 'XDG_DATA_HOME', 'XDG_CACHE_HOME', 'XDG_CONFIG_HOME', 'JVM_TEST_ARGS')) {
     $oldEnvironment[$name] = [Environment]::GetEnvironmentVariable($name)
 }
@@ -27,6 +29,34 @@ function Assert-Equal {
     }
 }
 
+function Invoke-TestProcess {
+    param([string]$FilePath, [string]$ArgumentText)
+    # Start-Process -Wait polls the job at one-second intervals in Windows
+    # PowerShell. Drain both pipes concurrently and wait on the process itself.
+    $process = New-Object Diagnostics.Process
+    $process.StartInfo.FileName = $FilePath
+    $process.StartInfo.Arguments = $ArgumentText
+    $process.StartInfo.WorkingDirectory = (Get-Location).ProviderPath
+    $process.StartInfo.UseShellExecute = $false
+    $process.StartInfo.CreateNoWindow = $true
+    $process.StartInfo.RedirectStandardOutput = $true
+    $process.StartInfo.RedirectStandardError = $true
+    try {
+        if (-not $process.Start()) { throw "Cannot start test process: $FilePath" }
+        $script:processCount++
+        $stdoutTask = $process.StandardOutput.ReadToEndAsync()
+        $stderrTask = $process.StandardError.ReadToEndAsync()
+        $process.WaitForExit()
+        return [pscustomobject]@{
+            ExitCode = $process.ExitCode
+            Out = $stdoutTask.GetAwaiter().GetResult()
+            Err = $stderrTask.GetAwaiter().GetResult()
+        }
+    } finally {
+        $process.Dispose()
+    }
+}
+
 function Invoke-JvmTest {
     param([string[]]$Arguments, [int]$ExpectedExitCode = 0, [switch]$Interactive,
         [switch]$Redirect, [switch]$Capture, [switch]$Streams)
@@ -62,12 +92,10 @@ function Invoke-JvmTest {
     $quotedArguments = @($allArguments | ForEach-Object {
         '"' + ([string]$_).Replace('"', '\"') + '"'
     })
-    $process = Start-Process -FilePath $powershellExe `
-        -ArgumentList ($quotedArguments -join ' ') -Wait -PassThru -NoNewWindow `
-        -RedirectStandardOutput $stdout -RedirectStandardError $stderr
+    $process = Invoke-TestProcess $powershellExe ($quotedArguments -join ' ')
     $code = $process.ExitCode
-    $outText = [IO.File]::ReadAllText($stdout)
-    $errText = [IO.File]::ReadAllText($stderr)
+    $outText = $process.Out
+    $errText = $process.Err
     if ($Redirect -or $Capture) {
         Assert-Equal $outText '' 'Output bypassed PowerShell stdout redirection.'
         Assert-Equal $errText '' 'Output bypassed PowerShell stderr redirection.'
@@ -76,7 +104,6 @@ function Invoke-JvmTest {
         Remove-Item -LiteralPath $redirectOut, $redirectErr -Force
     }
     $output = $outText + $errText
-    Remove-Item -LiteralPath $stdout, $stderr -Force
     if ($code -ne $ExpectedExitCode) {
         throw "jvm.ps1 $($Arguments -join ' ') exited $code; expected $ExpectedExitCode.`n$output"
     }
@@ -106,15 +133,10 @@ function Assert-DefaultUsage {
 
 function Invoke-JvmLauncherTest {
     param([string]$ArgumentText, [int]$ExpectedExitCode = 0)
-    $stdout = Join-Path $testRoot ([guid]::NewGuid().ToString('N') + '.out')
-    $stderr = Join-Path $testRoot ([guid]::NewGuid().ToString('N') + '.err')
     $command = '/d /s /c ""' + $launcherPath + '" ' + $ArgumentText + '"'
-    $process = Start-Process -FilePath (Join-Path ([Environment]::SystemDirectory) 'cmd.exe') `
-        -ArgumentList $command -Wait -PassThru -NoNewWindow `
-        -RedirectStandardOutput $stdout -RedirectStandardError $stderr
-    $outText = [IO.File]::ReadAllText($stdout).TrimEnd()
-    $errText = [IO.File]::ReadAllText($stderr).TrimEnd()
-    Remove-Item -LiteralPath $stdout, $stderr -Force
+    $process = Invoke-TestProcess (Join-Path ([Environment]::SystemDirectory) 'cmd.exe') $command
+    $outText = $process.Out.TrimEnd()
+    $errText = $process.Err.TrimEnd()
     Assert-Equal ([string]$process.ExitCode) ([string]$ExpectedExitCode) `
         "jvm.cmd $ArgumentText returned the wrong exit code. $outText $errText"
     return [pscustomobject]@{ Out = $outText; Err = $errText }
@@ -624,6 +646,7 @@ try {
 
     [Console]::Out.WriteLine("PASS: $script:passed PowerShell smoke checks (offline; synthetic JDKs) using $PowerShellExecutable.")
 } finally {
+    [Console]::Out.WriteLine(('PowerShell suite: {0:N2}s, {1} test processes' -f $suiteTimer.Elapsed.TotalSeconds, $script:processCount))
     if ((Get-Location).Path -eq $testRoot) { Pop-Location }
     foreach ($name in $oldEnvironment.Keys) {
         [Environment]::SetEnvironmentVariable($name, $oldEnvironment[$name])
diff --git a/tests/run.sh b/tests/run.sh
index 332d5ea..88b2ca7 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -16,8 +16,9 @@ mkdir -p "$HOME" "$TEMP/bin"
 TOOLS="$TEMP/bin"
 for tool in mkdir mktemp rm sed awk cat mv date cp; do
     path=$(command -v "$tool") || exit 1
-    printf '#!%s\nexec "%s" "$@"\n' "$BASH_BIN" "$path" > "$TOOLS/$tool"
-    chmod +x "$TOOLS/$tool" || exit 1
+    # MSYS shortcut links work without elevation and retain the executable's
+    # original DLL location. Do not add an interpreter to every utility call.
+    MSYS=winsymlinks ln -s "$path" "$TOOLS/$tool" || exit 1
 done
 export PATH=$TOOLS
 export TEST_SYSTEM=Linux TEST_MACHINE=x86_64 TEST_LIBC=glibc