I'm running TrueNas Scale from a VM. Why is because I need to run IMMICH and NextCloud. Docker Desktop has memory leaks and BSODs Windows anytime from 5 minutes to 12 hours. I will not run Linux. I don't have the space for another physical machine for TrueNas Scale. Virtual Machine it is.
Other reasons why I'm a Windows on bare metal and TrueNas on a VM is because the HTPC is performing quite a lot of other functions - it's a NAS, it's a web server for multiple websites, it runs all the arr apps and qbittorrent and sabnzbd and my wife uses it with mouse and keyboard to watch YouTube and other video streaming sites and we also use it for light productivity or to share things with guests. It sits behind our TV in the living room.
Windows from a VM from within HexOS has it's appeals, specifically Windows requires a reboot at least once a month for things like updates and other stuff. My only concern here is the user experience. If your wife used Windows from a VM on HexOS, could she click on something that takes her to the HexOS hypervisor (home screen) where she could do some damage? Also I'd have to require GPU acceleration for Windows in order to do things like decode 4K video and play it back on the TV. The more stable and/or "feature-complete" OS should be the hypervisor, in this case, for me anyways, Windows on metal wins.
For any curious, my post detailing my setup, specifically focusing on NextCloud: