I don’t know what server you’re running, but I have never had any issues with USB keyboards. They just work, including in the firmware. No drivers needed. Besides, a proper server motherboard will have IPMI so you can just remote into it.
I’ve had KVMs that don’t like the ‘fancier’ USB keyboards with NKRO. It would work, but it wouldn’t listen for its own ‘switch to different console’ hotkeys. Reconfiguring the keyboard to run in 6KRO-only mode addressed it, but not every keyboard can be configured that way.