This should be the last minirack post for awhile as it's 99.9% finished. It was a very fun build, and it's a heluva-lot quieter than what it replaced. I did lose network bandwidth, but the new cluster does exactly what it's supposed to. Live migrations are fast enough, iSCSI network means that the VMs are snappy storage-wise. The PiKVM + Switch fits perfectly in the basement.
The dual fans fixed the issue of the top Minisforum MS-A2 baking from the heat of the RPis, and the QNAP switch is a beast. I definitely recommend building in a minirack as they're adorable and very, very capable.