This is actually good advise. I am running ProxMox on a very old PC (3rd Gen i3 with 8GB of ram), and I really like it, which is why I wanted to move it to my server Box instead.
But now that you mention it, I may be better off keeping my UnRaid box as it is and use is as NAS/Storage exclusively and then build a good box to run everything else from ProxMox.
My wife is going to kill me in my sleep, lol.
After Ai watched Lempa's video virtualizing TrueNAS passing through all drives on ProxMox, I started searching to see if anyone had tried the same with UnRaid, and TechHut actually did it.
https://www.youtube.com/watch?v=ahOXQM4416Q
However, my use case is somewhat different than his, and he's just a hobbyist like me, so I'm much more comfortable asking in this community where it's highly likely that someone already crashed and burned before me, lol.
I'm thinking I'll take the advise of just building a new server for ProxMox, and then use my current UnRaid box exclusively for storage. That should be somewhat safer, right?