Sadly rr cannot work on software that makes any kind of call to GPUs, so its usefulness is pretty limited on a lot of larger software. But when it's usable, imo it's amazing.
If the UI is not GPU accelerated while you are recording, rr will work fine. You can even have GPU calls in the code while recording, they just can't be on code paths that are taken. So a simple command line flag that makes the code choose to use CPU rendering instead of GPU rendering should be fine.
That said, GPU rendering is one of the things that deterministic replay could be most useful for, so it's unfortunate that this doesn't work in rr for now.