It's 2023 everyone and there's finally a light at the end of this "crystalsky as external monitor" tunnel....even brighter as you can also use it as a recorder.
I have a attached a photo of my solution working with my Sony A7sII camera as a monitor and it can also record videos as the camera is recording as a backup or redundancy.
I can tell you this far, as long as you have an hdmi source, you will be able to use your Crystalsky to record anything from camera outputs, computer video signals and even your game consoles. Also, given it has 2 micro SD card slots this will be great as you can expand storage for recorded footage.
I just discovered this tonight but if there is any other interest in this solution do let me know so I can make a proper step by step video tutorial and have these monitors running out in the wild again!
Thanks everyone!