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.
> For as long as we’re able (and assuming the cooperation of the extension authors), Brave will continue to support some privacy-relevant MV2 extensions—specifically AdGuard, NoScript, uBlock Origin, and uMatrix
Once Google removes MV2 and it's supporting code, Brave is not going to shoulder the cost of keeping all of that patched to run on newer builds of Chromium. Especially not because their own blocking doesn't rely on it, uMatrix has been deprecated since 2021, and AdGuard is already committed to transitioning to MV3.