If any new fork of chromium support manifest 2 forever, while maintaining the other upstream updates, that will be my go to browser. May be Opera can resurrect.
I salute you for your bravery, I can't even make myself comfortable with the idea of switching from Firefox to Librewolf, never mind "any new fork" of a browser. The security implications are just too severe - malicious code, lingering vulnerabilities, project abandonment, etc.