I acquired a Rockpi4 in the hope to use it blob-free. But I'd love to see vendors trying to ryf-certify it. Do you (or any other vendor) have plans to sell or certify it?
Also in your list of tasks you list ROCKPro64. Although I really like pine64 steps, I think the best rk3399 device for such a task is the Rock Pi 4 Model A Plus, it's got a faster processor, no wifi and the usb-c port is used for power only: no need to care about blobs for eDP! So, if you are thinking about a board to support, I'd suggest you to think about the Rock Pi 4 Model A Plus.