

A big problem with such forks (same with packages made by Linux distributors) is that there is a delay between official FF release and the release of the corresponding update of the fork.
That’s called a patched downstream, not a fork.
LibreOffice was a fork of OpenOffice. OpenBSD was a fork of NetBSD.
Likely this, and those 100bln are a lot for the right people involved in the tremendous effort that will unfortunately fail, but you never know