I’m one of the developers of Clone Hero and also a former developer on FoFiX(its what the video you linked to is, a fork of fof) s I’m in a special place to be able to answer this. Tldr: FoFiX was hot trash to say the least.

I’m one of the developers of clone hero, we are almost done with our next Major release which does have full drums support. Including the ability to use midi based electronic drum kits! We don't currently have vocals support unfortunately.

Edit: wrong comment

So regarding frame independant physics it is mostly possible even on a single thread. I recommendd reading this article on the topic.