It is 2020 and Facilities just purchased a total campus door access control system... That runs entirely on 10 Half Duplex

Yeah.

Each door gets a small module that mounts above the ceiling tile. This module accepts input from the card reader, switches power on/off to the mag locks, etc. It is managed and powered over Ethernet. Each module has a NIC that only operates at 10 Half Duplex.

Most of our switches technically support it for now, but I worry about our next access switch refresh. I get the feeling we're going to end up buying a bunch of EOL or crappy Netgear 100MB switches to "convert" this connection.