The one i linked is both a router and or switch, you can get cheap switches for like $300 that do really well.

many people just buy junk like this https://www.amazon.com/Mikrotik-Router-Switch-CRS305-CRS305-1G-4S/dp/B08437RDM1 it’s cheaper in the long run.

You will need a good 10Gb nic, I have been using Intel nic’s if you use a Intrusion Prevention System that can eat away at the CPU, also more RAM helps like 8GB’s or more for IPS, I use 16GB’s for IPS + ZFS and a nice Switch can help a lot as it can do DNS and the works, more or less i use a firewall box to a Switch and use a Layer 3 Switch for routing, some can do 20+Gb’s routing.

someone on reddit had this working 6 mo’s ago, I think they had 2 VM’s running games from one GPU it was on /r/vfio and they said the Windows Driver was being worked on as well.