F12E/F7 video support

I know it isn't what you asked, but I really recommend the F12e. The F4/F7 has a pretty lousy Video driver, fewer selectable video channels (less compatibility), and the same CPU as the 7e (very limited). the F12e is really only limited by its tiny SPI memory which would be easy to replace. It is obviously a lot more expensive, and it is a lot bigger and heavier, but I think it is ALMOST a perfect all around transmitter. My main gripes are that they could have used a better LCD driver for the screen, and the bigger SPI flash. Also be aware that while as of now all 3 are supported by Deviation, the ports are still very crude, and there remains quite a bit of GUI work to do.

If I had to choose, I would keep only my F12e and my 7e-ultimate and would get rid of all the others (and I own nearly all of Walkera's Devo series (I think I'm only missing an F4, 6S and F12)). If I could only have one, it would probably be the F12E.

Having spent lots of time with the touch screen and the B&W screen, I prefer the high-contrast of the b&w screens. I find the touch screen to be really gimicky, and very rarely see a need for it. The F12E screen is easier to read than the 12S. The 12S is a bit better built (it has a very nice chassis), but I think the video outweighs the benefts of the 12S. I also like the button layout on the F12E, they are much more intuitive to use in my experience. The F12E is also a bit cheaper. Honestly, the 12S is also a really good transmitter, but I think the F12E is better overall. That said the 12S has a lot more SPIFlash which could be important to some. If you want a big transmitter they are both good choices, but you started by discussing video enabled options.

probably. Do you have some candidates in mind? I think we need a minimum SPI frequency of ~20MHz and 4kB blocks (minimum erase size).

I don't see much problem. The big difference is the removal of AAI-Word-Programming, which is replaced by extending the AGE_PROG command. We cuold either fall back to single-byte write (like on the F7/F12e) or add some additional code to handle this.