The FSF must decide whether to endorse a product, and it must be requested by the supplier. So if a product could be endorsed, but isn't, it's either being reviewed or has not been submitted by the vendor.
In fact, I'm interested in their product commercially for Minifree, and also interested in terms of Libreboot. You can replace the default uboot firmware with coreboot, which offers many more features and there's where my company could really offer some nice custom services.
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?
Looking forward to it. Getting an rk3399 device ryf-certified would be great. They have accelerated 3d graphics and video codecs that are (AFAIK) fully supported by fully free software. It would be, although not very powerful, the most modern affordable ryf-certified device available. I really hope you do 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.
In fact, I'm interested in their product commercially for Minifree, and also interested in terms of Libreboot. You can replace the default uboot firmware with coreboot, which offers many more features and there's where my company could really offer some nice custom services.
It has been on TODO for Libreboot since May 2021: https://libreboot.org/tasks/#investigate-u-boot
It is mentioned here, in the context of u-boot specifically, but I'm aware that coreboot also supports it.