I'm happy doing some soldering. Is there anything that TinyPilot has that Pi-KVM doesn't?
Has Pi-KVM added support for the HDMI dongle you used?
I'd say, in short, Pi-KVM is more feature rich, while TinyPilot is simpler and more approachable with less functionality.
Pi-KVM has several nice features that TinyPilot doesn't yet have, including power management, mouse support, authentication, TLS, and USB storage mounting.
TinyPilot has a quicker install. Pi-KVM requires you to compile the OS locally, which takes about an hour. If you've got a Raspberry Pi OS system (aka Raspbian) already, you can configure it for TinyPilot with two commands, and the install takes 5-10 minutes.
One of my goals with TinyPilot was to avoid a requirement for soldering/jumper cables, but if you don't mind soldering, that might not matter much to you. Pi-KVM works without soldering as well, but the documentation assumes soldering/breadboards.
I hope that there's space for both projects, and Max and I have talked about ways to potentially collaborate.