OpenWrt on real hardware is no problem ...
I have a Nanopi R2S as main router, 2 Archer C7 and a WDR4900 as dump AP's, and 3 * GS108T as managed switches running. (I'm using several VLAN's) A x86 FreiFunk Offloader in fact is OpenWrt too.
So I would like to build a test environment on Proxmox...