I use pfSense for the stability of it.
Netgate as a company has certainly done a few things which have had me looking at other router options but at the moment, pfSense CE works, is stable, and I don't need to faff with it, so I'm happy staying put.
If you're ok with blowing away Proxmox and starting fresh then yes, that's something you can do.
I will be doing the same on a Dell miniPC soon but with smaller SSDs.