Wow… thank you for that in-depth explanation! This is incredibly helpful and it’s clear that I’ve got a lot of reading to do 
I’ve had a read through your other post and that definitely feels like the experience I’ve had with the current state of NixOS documentation. I’ve been trying to get into NixOS for about a year now, but I often find myself running into undocumented options and no clear guidance most of the time, which makes it pretty hard to commit. What does exist seems to be scattered and buried across a myriad of unofficial docs, tutorials, and wikis with no clear thread to tie everything together. I’m currently trying to recruit people for a rewrite of the QEMU docs for similar reasons, as I have a hypothesis that this is a very powerful use case for NixOS which is currently untapped.
I’ll try your recommended config and see how that goes!