If chunks of functionality are missing from MV3 with no available alternative, if the replacement is really at such an early stage of development like this, it would be silly not to delay mandatory adoption by another year or two. (Including requiring new extensions to be MV3 - from what I'm reading here, it sounds like you're really not ready for that and should undo it.) Please don't be another https://goomics.net/50/. It's so much worse when it happens externally in an ecosystem.