diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index cebc2d1..6837d87 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,9 +2,9 @@ name: Build (Windows)
 
 on:
   push:
-    branches: [ "master", "main" ]
+    branches: [ "master", "main", "sow/2026-Q2" ]
   pull_request:
-    branches: [ "master", "main" ]
+    branches: [ "master", "main", "sow/2026-Q2" ]
   workflow_dispatch:
 
 jobs:
@@ -55,10 +55,27 @@ jobs:
           $deps = $buildOrder[0..($buildOrder.Count-2)]
           foreach ($r in $deps) {
             if (Test-Path $r) { continue }
-            Write-Host "Cloning https://github.com/$org/$r.git"
-            git clone --depth 1 "https://github.com/$org/$r.git" $r
+            $headRef = '${{ github.head_ref }}'
+            $candidates = @()
+            if ($headRef) { $candidates += $headRef }
+            $candidates += 'sow/2026-Q2'
+            $cloned = $false
+            foreach ($cand in $candidates) {
+              $has = (git ls-remote --heads "https://github.com/$org/$r.git" $cand 2>$null | Out-String).Trim()
+              if ($has) {
+                Write-Host "Cloning $org/$r @ $cand"
+                git clone --depth 1 --branch $cand "https://github.com/$org/$r.git" $r
+                $cloned = $true
+                break
+              }
+            }
+            if (-not $cloned) {
+              Write-Host "Cloning $org/$r @ default branch"
+              git clone --depth 1 "https://github.com/$org/$r.git" $r
+            }
           }
 
+
           # Ensure ReferencePath exists even before SAM_Windows builds
           New-Item -ItemType Directory -Force -Path "SAM_Windows\build" | Out-Null
 
diff --git a/.github/workflows/spdx-check.yml b/.github/workflows/spdx-check.yml
index 269d562..e386bd3 100644
--- a/.github/workflows/spdx-check.yml
+++ b/.github/workflows/spdx-check.yml
@@ -2,44 +2,89 @@ name: SPDX + Copyright header check
 
 on:
   pull_request:
+  workflow_dispatch:
 
 jobs:
   spdx:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout repository
+        uses: actions/checkout@v5
         with:
           fetch-depth: 0
 
       - name: Check header in changed .cs files
+        shell: bash
         run: |
-          set -e
-          BASE="${{ github.event.pull_request.base.sha }}"
-          HEAD="${{ github.event.pull_request.head.sha }}"
+          set -euo pipefail
+
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            BASE="${{ github.event.pull_request.base.sha }}"
+            HEAD="${{ github.event.pull_request.head.sha }}"
+          else
+            HEAD="${{ github.sha }}"
+            BASE="$(git rev-parse "${HEAD}^" 2>/dev/null || true)"
+          fi
 
-          FILES=$(git diff --name-only "$BASE" "$HEAD" -- '*.cs' || true)
+          echo "Base SHA: ${BASE:-<none>}"
+          echo "Head SHA: $HEAD"
+          echo
 
-          if [ -z "$FILES" ]; then
+          if [ -z "${BASE:-}" ]; then
+            mapfile -t files < <(git ls-files '*.cs')
+          else
+            mapfile -t files < <(git diff --diff-filter=ACMR --name-only "$BASE" "$HEAD" -- '*.cs' || true)
+          fi
+
+          if [ "${#files[@]}" -eq 0 ]; then
             echo "No C# files changed."
             exit 0
           fi
 
-          MISSING=""
-          for f in $FILES; do
-            HEADBLOCK=$(head -n 6 "$f")
+          echo "Changed C# files:"
+          printf ' - %s\n' "${files[@]}"
+          echo
+
+          missing=()
+
+          for f in "${files[@]}"; do
+            if [ ! -f "$f" ]; then
+              echo "Skipping missing file: $f"
+              continue
+            fi
+
+            headblock="$(head -n 20 "$f" | sed '1s/^\xEF\xBB\xBF//' | tr -d '\r')"
+
+            echo "Checking: $f"
+
+            if ! grep -q "SPDX-License-Identifier: LGPL-3.0-or-later" <<< "$headblock"; then
+              echo "  Missing SPDX line"
+              missing+=("$f")
+              continue
+            fi
+
+            if ! grep -qE "Copyright \(c\) 2020[-–]2026 Michal Dengusiak & Jakub Ziolkowski and contributors" <<< "$headblock"; then
+              echo "  Missing copyright line"
+              missing+=("$f")
+              continue
+            fi
 
-            echo "$HEADBLOCK" | grep -q "// SPDX-License-Identifier: LGPL-3.0-or-later" || MISSING="$MISSING $f"
-            echo "$HEADBLOCK" | grep -q "// Copyright (c) 2020–2026 Michal Dengusiak & Jakub Ziolkowski and contributors" || MISSING="$MISSING $f"
+            echo "  OK"
           done
 
-          if [ -n "$MISSING" ]; then
-            echo "❌ Missing required header in:"
-            for f in $MISSING; do echo " - $f"; done
-            echo ""
-            echo "Each changed .cs file must start with:"
+          echo
+          if [ "${#missing[@]}" -gt 0 ]; then
+            echo "Missing required header in:"
+            printf ' - %s\n' "${missing[@]}"
+            echo
+            echo "Each checked .cs file must contain within the first 20 lines:"
             echo "// SPDX-License-Identifier: LGPL-3.0-or-later"
-            echo "// Copyright (c) 2020–2026 Michal Dengusiak & Jakub Ziolkowski and contributors"
+            echo "// Copyright (c) 2020-2026 Michal Dengusiak & Jakub Ziolkowski and contributors"
             exit 1
           fi
 
-          echo "✅ SPDX + copyright headers OK."
+          echo "SPDX + copyright headers OK."
\ No newline at end of file
diff --git a/Grasshopper/SAM.Core.Grasshopper.SQL/SAM.Core.Grasshopper.SQL.csproj b/Grasshopper/SAM.Core.Grasshopper.SQL/SAM.Core.Grasshopper.SQL.csproj
index 096cb33..83a2ad0 100644
--- a/Grasshopper/SAM.Core.Grasshopper.SQL/SAM.Core.Grasshopper.SQL.csproj
+++ b/Grasshopper/SAM.Core.Grasshopper.SQL/SAM.Core.Grasshopper.SQL.csproj
@@ -60,9 +60,7 @@
       <ExcludeAssets>runtime</ExcludeAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
-    <PackageReference Include="Newtonsoft.Json">
-      <Version>13.0.3</Version>
-    </PackageReference>
+    <PackageReference Include="System.Text.Json" Version="10.0.8" />
   </ItemGroup>
   <PropertyGroup />
   <PropertyGroup>
diff --git a/SAM_SQL/SAM.Core.SQL/SAM.Core.SQL.csproj b/SAM_SQL/SAM.Core.SQL/SAM.Core.SQL.csproj
index 598e51e..9d392d3 100644
--- a/SAM_SQL/SAM.Core.SQL/SAM.Core.SQL.csproj
+++ b/SAM_SQL/SAM.Core.SQL/SAM.Core.SQL.csproj
@@ -36,7 +36,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageReference Include="System.Data.DataSetExtensions" Version="4.5.0" />
-    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageReference Include="System.Text.Json" Version="10.0.8" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="System.Data.SqlClient">