> I've never heard of anyone else having done anything like this. This surprises me! But, surely, if someone else did it, someone would have told me about it? If you know of another, please let me know!
I never had the tenacity to consider my build "finished," and definitely didn't have your budget, but I built a 5-player room[1] for DotA 2 back in 2013.
I got really lucky with hardware selection and ended up fighting with various bugs over the years... diagnosing a broken video card was an exercise in frustration because the virtualization layer made BSODs impossible to see.
I went with local disk-per-VM because latency matters more than throughput, and I'd been doing iSCSI boot for such a long time that I was intimately familiar with the downsides.
I love your setup (thanks for taking the time to share this BTW) and would love to know if you ever get the local CoW working.
My only tech-related comment is that I will also confirm that those 10G cards are indeed trash, and would humbly suggest an Intel-based eBay special. You could still load iPXE (I assume you're using it) from the onboard NIC, continue using it for WoL, but shift the netboot over to the add-in card via a script, and probably get better stability and performance.
[1]: https://imgur.com/a/4x4-four-desktops-one-system-kWyH4