Yes you can do the same on Windows.

https://www.grc.com/inspectre.htm

You have to recompile the kernel to remove some mitigations about "indirect branching", namely you must have alternative windows kernels.

Do you have those windows kernels?

Interesting, did not know you could do that but it does make sense. Make sure it’s air gapped.

Only really on CPUs with the vulnerability

mitigations do slow all CPUs, even those without the vulns.

You need alternative linux kernels with their modules.