diff --git a/.github/workflows/base-installer-cd.yml b/.github/workflows/base-installer-cd.yml
index 709be6dc09..f752cc326d 100644
--- a/.github/workflows/base-installer-cd.yml
+++ b/.github/workflows/base-installer-cd.yml
@@ -156,7 +156,7 @@ jobs:
         id: build_and_test
         shell: powershell
         run: |
-          .\build.ps1 -BuildInstaller -Configuration Release -Verbosity detailed -BuildTests -RunTests -TestFilter 'TestCategory!=DesktopRequired' -MsBuildArgs @("/bl") | Tee-Object -FilePath build.log
+          .\build.ps1 -BuildInstaller -Configuration Release -Verbosity detailed -RunTests -TestFilter 'TestCategory!=DesktopRequired' -MsBuildArgs @("/bl") | Tee-Object -FilePath build.log
 
       - name: Scan Build Output
         shell: powershell
diff --git a/.github/workflows/patch-installer-cd.yml b/.github/workflows/patch-installer-cd.yml
index 50f6af2400..9d65493ddf 100644
--- a/.github/workflows/patch-installer-cd.yml
+++ b/.github/workflows/patch-installer-cd.yml
@@ -225,7 +225,7 @@ jobs:
         shell: powershell
         run: |
           Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\.NETFramework\AppContext"
-          .\build.ps1 -BuildPatch -Configuration Release -Verbosity detailed -BuildTests -RunTests -TestFilter 'TestCategory!=DesktopRequired' -MsBuildArgs @("/bl") | Tee-Object -FilePath build.log
+          .\build.ps1 -BuildPatch -Configuration Release -Verbosity detailed -RunTests -TestFilter 'TestCategory!=DesktopRequired' -MsBuildArgs @("/bl") | Tee-Object -FilePath build.log
 
       - name: Scan Build Output
         shell: powershell
@@ -293,3 +293,5 @@ jobs:
           path: |
             ./*.log
             ./*.binlog
+            ./PatchableInstaller/CreateUpdatePatch/Master/AppHarvest.wxs
+            ./PatchableInstaller/CreateUpdatePatch/Update/AppHarvest.wxs
diff --git a/.gitignore b/.gitignore
index 5ed27ca330..47476587d9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -63,6 +63,7 @@ _user.mak.lnx
 *.usertasks
 *.resources
 *.bak
+*.fwdata.lock
 *.swp
 *.pyc
 *.log
diff --git a/Build/Agent/Setup-InstallerBuild.ps1 b/Build/Agent/Setup-InstallerBuild.ps1
index bb4b203c76..32f6e4ae92 100644
--- a/Build/Agent/Setup-InstallerBuild.ps1
+++ b/Build/Agent/Setup-InstallerBuild.ps1
@@ -320,21 +320,22 @@ if ($issues.Count -eq 0) {
 		}
 	}
 
+	# REVIEW (Hasso) 2026.03: why are we encouraging direct msbuild calls over $(fwrt)/Build.ps1 calls?
 	Write-Host "`nTo build installers:" -ForegroundColor White
 
 	if ($vsDevEnvActive) {
 		# VS Developer environment is active, show simple commands
 		Write-Host ""
 		Write-Host "  # Restore packages" -ForegroundColor Gray
-		Write-Host "  msbuild Build/InstallerBuild.proj /t:RestorePackages /p:Configuration=Debug /p:Platform=x64" -ForegroundColor Cyan
+		Write-Host "  msbuild Build/InstallerBuild.proj /t:RestorePackages /p:Configuration=Release /p:Platform=x64" -ForegroundColor Cyan
 		Write-Host ""
 		Write-Host "  # Build base installer" -ForegroundColor Gray
-		Write-Host "  msbuild Build/InstallerBuild.proj /t:BuildInstaller /p:Configuration=Debug /p:Platform=x64 /p:config=release /m /v:n" -ForegroundColor Cyan
+		Write-Host "  msbuild Build/InstallerBuild.proj /t:BuildInstaller /p:Configuration=Release /p:Platform=x64 /p:config=release /m /v:n" -ForegroundColor Cyan
 		Write-Host ""
 
 		if ($SetupPatch) {
 			Write-Host "  # Build patch installer" -ForegroundColor Gray
-			Write-Host "  msbuild Build/InstallerBuild.proj /t:BuildPatchInstaller /p:Configuration=Debug /p:Platform=x64 /p:config=release /m /v:n" -ForegroundColor Cyan
+			Write-Host "  msbuild Build/InstallerBuild.proj /t:BuildPatchInstaller /p:Configuration=Release /p:Platform=x64 /p:config=release /m /v:n" -ForegroundColor Cyan
 			Write-Host ""
 		}
 	} else {
@@ -344,15 +345,15 @@ if ($issues.Count -eq 0) {
 		Write-Host "  # Option 2: Use these one-liner commands from any PowerShell:" -ForegroundColor Gray
 		Write-Host ""
 		Write-Host "  # Restore packages" -ForegroundColor Gray
-		Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:RestorePackages /p:Configuration=Debug /p:Platform=x64"' -ForegroundColor Cyan
+		Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:RestorePackages /p:Configuration=Release /p:Platform=x64"' -ForegroundColor Cyan
 		Write-Host ""
 		Write-Host "  # Build base installer" -ForegroundColor Gray
-		Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:BuildInstaller /p:Configuration=Debug /p:Platform=x64 /p:config=release /m /v:n"' -ForegroundColor Cyan
+		Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:BuildInstaller /p:Configuration=Release /p:Platform=x64 /p:config=release /m /v:n"' -ForegroundColor Cyan
 		Write-Host ""
 
 		if ($SetupPatch) {
 			Write-Host "  # Build patch installer" -ForegroundColor Gray
-			Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:BuildPatchInstaller /p:Configuration=Debug /p:Platform=x64 /p:config=release /m /v:n"' -ForegroundColor Cyan
+			Write-Host '  cmd /c "call ""C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\Tools\VsDevCmd.bat"" -arch=amd64 >nul && msbuild Build/InstallerBuild.proj /t:BuildPatchInstaller /p:Configuration=Release /p:Platform=x64 /p:config=release /m /v:n"' -ForegroundColor Cyan
 			Write-Host ""
 		}
 	}
diff --git a/Build/PackageRestore.targets b/Build/PackageRestore.targets
index 8beaa21f3d..1881e0073b 100644
--- a/Build/PackageRestore.targets
+++ b/Build/PackageRestore.targets
@@ -317,10 +317,7 @@
 	     SIL.Machine.Morphology.HermitCrab.dll are now provided by NuGet PackageReference. -->
 	<ItemGroup>
 		<!-- GeckofxHtmlToPdf dependency (shipped alongside FieldWorksPdfMaker.exe) -->
-		<DownloadedFiles
-			Include="$(DownloadsDir)/Args.dll"
-			Condition="Exists('$(DownloadsDir)/Args.dll')"
-		/>
+		<DownloadedFiles Include="$(DownloadsDir)/Args.dll" />
 	</ItemGroup>
 
 	<!-- ======================================================================================== -->
@@ -451,6 +448,7 @@
 		/>
 		<!-- Copy native/special-case artifacts that PackageReference doesn't handle automatically -->
 		<ItemGroup>
+			<!-- REVIEW (Hasso) 2026.03: when do we expect any of these files not to exist? If they don't, do we really want to continue building merrily? -->
 			<ExistingPalasoFiles
 				Include="@(PalasoFiles)"
 				Condition="Exists('$(PalasoArtifactsDir)/%(Identity)')"
@@ -459,10 +457,6 @@
 				Include="@(ChorusFiles)"
 				Condition="Exists('$(ChorusArtifactsDir)/%(Identity)')"
 			/>
-			<ExistingDownloadedFiles
-				Include="@(DownloadedFiles)"
-				Condition="Exists('%(Identity)')"
-			/>
 		</ItemGroup>
 		<!--
 			Expected Warning: "Missing Palaso native files"
@@ -506,7 +500,7 @@
 		/>
 		<!-- Copy pre-populated binaries (Args.dll for GeckofxHtmlToPdf) -->
 		<Copy
-			SourceFiles="@(ExistingDownloadedFiles)"
+			SourceFiles="@(DownloadedFiles)"
 			DestinationFolder="$(dir-outputBase)"
 			SkipUnchangedFiles="true"
 			OverwriteReadOnlyFiles="true"
@@ -563,6 +557,7 @@
 			     MSBuild's automatic assembly resolution copies them to the output directory.
 			     SIL.BuildTasks is now a PackageReference in FwBuildTasks.csproj. -->
 		</ItemGroup>
+		<!-- REVIEW (Hasso) 2026.03: do we still need to copy NuGottenFiles explicitly here? -->
 		<Copy
 			SourceFiles="@(NuGottenFiles)"
 			DestinationFolder="$(dir-outputBase)/%(RecursiveDir)"
diff --git a/build.ps1 b/build.ps1
index 795e3a06d3..b639e3f379 100644
--- a/build.ps1
+++ b/build.ps1
@@ -197,7 +197,8 @@ if ($Configuration -eq 'Release' -and -not $isGitHubActions) {
 	}
 }
 
-# ===========ed Module
+# =============================================================================
+# Import FwBuildHelpers Module (for building build tasks)
 # =============================================================================
 
 $helpersPath = Join-Path $PSScriptRoot "Build/Agent/FwBuildHelpers.psm1"
@@ -610,7 +611,7 @@ try {
 			Invoke-MSBuild `
 				-Arguments (@('Build/InstallerBuild.proj', "/t:Build$BaseOrPatch", '/p:config=release', "/p:InstallerToolset=$InstallerToolset", $installerCleanArg) + `
 					$InstallerMsBuildArgs) `
-				-Description '$BaseOrPatch Build' `
+				-Description "$BaseOrPatch Build" `
 				-LogPath $LogFile `
 				-TailLines $TailLines