Any way to make it have two forearm bones? for pronation aka twisting
Nope, If you want that just use normal Rigify. It has two for each arm bone and leg.bone. That also makes it incompatible for game dev retargeting to any skeletons following the Game Dev standard
There is a standard skeleton that the major Game engines use and expect. It's a specific number of bones, in a specific hierarchy. If you stray from it, you can't retarget animations sourced from different places or libraries. So Rigodotify is strict because its purpose is for Game Dev primarilu, and so won't stray from the standards the industry is using.