Thanks for opening this discussion! Mainly I want to be a spectator at this point, and just get my finger on the pulse of what you all want or are imagining.
My thought is more of a devboard (like Raspberry Pi or Arduino), but with perhaps a module version, of what is currently the Memory Palace/TBC2 platform. There are several devboards out there with video in and out, but it is pretty much always HDMI only and the boards with more than a single input are few. What I think we could offer is the devboard with at least two external video input channels and an output that runs synchronous to the inputs. This means you have proper analog genlocked I/O, and the device can then be modular and expandable. We would put into place all the basic infrastructure in the FPGA for time base correction/frame sync, frame buffering, and all the drivers. So it would effectively be a user scriptable video mixer/effects processor. Add MIDI controller and code to make pretty much whatever dedicated machine you wanted.