Either trueNAS or unraid work as a vm in Proxmox, but there’s some caveats. You have to pass the whole hba/lsi pcie device to the vm so you can’t split the backplane of the server.

I can’t speak to the all in one dream machine, though I’m sure it’s similar in capability to my UDM pro, which has been fairly solid for me and only really has had trouble when I induced it myself. It’s definitely much more complex and open than most home routers, and allows you to set every single thing you can think of, the drawback though is that it’s not as automated as some home routers and you need to know what you are setting more in depth when you step off the auto modes. Overall I’ve been very happy with my unifi setup. I also use Protect and I’m looking to set up Access too soon(ish).