That guy in the middle seems like a real jackass.
zork
You can't tell me what to do!
"That's crazy, you're crazy."
PiKVM is a collection of tools rolled into a distro to make keyboard/mouse input and attaching an emulated install media (virtual USB disk using ISO files) easily possible through a VNC-based web application. The idea is you can just build your own using the same software on different hardware, but it's aimed at using a raspberry pi for low power consumption, portability, and it has specific hardware compatibility with a HAT/addon board. The software can also make "reverse connections" through a remote NAT for support purposes, and you'd just port forward on your end. There are a lot of well thought out features in PiKVM (hardware) that make it much more convenient than building your own solution. You could install PiKVM on a different system than a Pi and try to make it work with your configuration.. You'd probably lose things like simulated power button press and virtual USB storage support. You might consider alternatives like PXE/netboot and wake-on-lan for those, but that might not always work for you.
(YMMV, I have not tried running PiKVM on an x86 cpu)
Lazy journalism. Crazies gonna crazy.
I can't offer advice, but I do support this idea! Consolidate the sports!
As long as you're certain your wireguard server works from other networks.. You could use nginx as a proxy to have your server accept incoming traffic from UDP port 53 (DNS)... But, be careful!
I would strongly suggest you whitelist the retrictive network for use on UDP port 53. Is the WAN IP static on the restrictive network? Do you know the size of the WAN subnet? I'd try a quick test over UDP port 53 using nginx, then close it up. If it works, create your firewall rule to whitelist only the restrictive network and Bob's your aunt.