Back when I did my setup,
there wasn’t a clear guide on the matter though, and it was rather hard to setup.
If you’re interested, I can link you all my bookmarks on the matter which I made back then though, however none of them were for Fedora / Nvidia specific.
For the pass-through mode,
I use VFIO (Virtual Function Input Output) with kernel / grub configurations, to always dedicate one of my 2 GPUs for the KVM (Kernel Virtual Machine).
You’d be looking for hot-plugging/hot-swapping your GPU instead, to un-attach your GPU from Linux and re-attach it to your Windows KVM when it boots.
Back when I was setting up my system, this was not possible on AMD yet due to a bug (Can’t vouch for Nvidia or if the AMD bug is fixed by now though)