What are you imagining? If this is desktop then most of the extensions are going to be standard.

The only reason they're optional is because I'm using the same instruction set on my Pico, so no it doesn't have floating point, and I believe it has integer divide but I wouldn't be surprised if it didn't.

And the extensions are in groups, a good chunk of which are compressed instructions, which unless you're writing assembly, you don't need to worry about.

In fact most of this you don't need to worry about unless youre writing assembly.

Electronics distributors search engines tend to work extremely poorly and if you try to overload them with an absurd variety of niche extensions, then nobody is going to find the right RISC V MCU for their needs.