Host machine hangs when Big Sur or Monterey VM boots

Really depends on what apps you are running in the VM.
eg Safari and Xcode seem to perform better with Metal hardware-accelerated graphics using Apple Paravirtualized Graphics (and some other Safari issues appear to be fixed now in both video adapters).

Sadly it's still a bit of a crapshoot with other apps. eg Visual Studio Code rendering is broken in both video adapters.