Nice work! FWIW, you can still use Manifest V2 extensions, like uMatrix, uBlock Origin, or Violentmonkey, in Chrome by passing command line flags. For example, on macOS:

    open -b com.google.Chrome --new --args --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled

When Google finally nerfs that, it is past time to move to Firefox or Brave, the latter of which has explicitly announced uMatrix support.