or make one yourself:
https://github.com/espkvm/espkvm
Also they say they are open sourcing the reference implementation of the "JetKVM OS Services" and the firmware of the "JetKVM Mini".
My point is more that it is way easier to make mistakes in source than it is to review said source in a project like this. So, to me, it is kind of risky to use something very green that is meant to be used as a network appliance more or less.
It started as a firmware for myself: I wanted a KVM, but not a Linux system inside one. A colleague talked me into publishing it and it grew from there. It runs on ESP32-P4 dev boards, no custom hardware.
I am not saying it is better than JetKVM. What I find more interesting is that the Mini landed on the same chip. Their stack is completely different from the Linux JetKVM, so it must be a rewrite from scratch - a sign the idea of a KVM without an OS holds up.
Have you considered using usb-hdmi capture dongle instead of using hdmi-csi. That is my idea, you bring your own capture dongle, plug it in and good to go. The esp32-s3 (and P4 i guess) support usb host, and there is uvc example from esp-idf.