What are too currently using for your OpenWRT router? I just got one of these and I would highly recommend it: a.aliexpress.com/_mq4HxaS

Get the N100 barebones version because you can slap an SSD and RAM in there for cheaper and have more selection. It has four 2.5Gb NICs and the internal PCIE slot for a WiFI card if you really want, though I would recommend getting a Ubiquiti AP to go along with it.

You can put OPNsense on it bare metal, or proxmox and then run your network related VMs there instead of your main server. Your choice.