Some other FDS issues with the Everdrive N8 Pro. Here is a spreadsheet showing the compatibility we found with every FDS game, on both regular Everdrive and Pro, both on latest firmware.
Green works.
Pink works on Pro, but not regular N8.
Red does not work on either.
https://docs.google.com/spreadsheets/d/1frtgSgFAacAPj3C2H6mH44mfyAXRRbU35AdM5w-JkHw/edit?usp=sharing
Re: Dead Zone on FDS, I've been trying to play the recently released English translation on my OG EverDrive N8, and while it technically works as indicated, you cannot save without switching to Side A, and it is somewhat critical to save often in text adventures. I assume the manual switch on the N8 Pro would make it possible to switch back to Side A to save your game.
I think disk sides are stored in FDS image files sequentially, this includes additional disks in multidisk games: 1A, 1B, 2A, 2B etc.
There are no games that spans more than 2 disks (4 sides), but there is technically no limit and a possibility for homebrew to have more. I don't have a pro yet, but I imagine that if you are on 1B on a 2-disk game and needs to return to side A to save, you would need to press the button 3 times to go back to 1A (or however the disk swap works).
In that compatibility list, what is the problem with the Famicom Mukashibanashi games, the Famicom Tantei Club games, Tantei Jinguuji Saburou and Time Twist? If the FDS button works as it should, it should be possible to switch to any side at any time like on a real FDS, that's the point of the button.