Maybe it is worth removing telemetry, enabling https and adding uBO by default to firefox? Standart firefox is not well suited for the most secure OS. I love librewolf. I read " Kicksecure Default Browser - Development Considerations". Maybe tor browser without tor network?
Worthwhile yes, but forking a browser is not possible with available development resources. Documented here:
In-House Browser Development
Documented just now:
Tor Browser without Tor
It’s not indeed. However, this is an unsolvable issue. The conclusion remains the same.