Manifest v3 is quite the bitch. Why break something that works fine?
The transition is giving extension developers everywhere a headache. Even I am trying to migrate The Marvelous Suspender to Manifest v3 but it's so complicated and is harder than I thought it would be.
There is one organizational policy that will allow people to enable Manifest v2 extensions on their browsers for at least one more year.
https://gist.github.com/velzie/053ffedeaecea1a801a2769ab86ab376