We don't yet support newer types like fp8 and fp4, that's actually my next project. I'm the only contributor with the hardware to actually use the new types, so it's a bit bottlenecked on a single person right now. But yes, the example is rather simplistic, should probably work on that some time once I'm done updating the feature set to Blackwell.
Isn't there a CPU-based "emulator" in Nvidia dev tools?