How to play itch.io games on the Steam Deck

Would it be possible to add an option to the itch desktop app to do this automatically?
Navigating Desktop-Steam’s file chooser on the Steam Deck is quite a hassle in particular, so even if it was available only on that system, it would help a lot. If you could somehow also automatically configure the library image, that would be incredible.

The itch app itself unfortunately doesn’t work in gaming mode. It would be neat if that was available too, especially if it could then add the games to Steam without going through desktop mode.
(Using the same executable detection that starting one normally uses, that is, since not everything has the .itch.toml.)

It mostly works great otherwise, with some mild drawbacks with games not supporting 16:10 or the native resolution directly (which causes borders or rarely some blurriness). Controls (in gaming mode) are less of an issue, usually at least one of the presets already covers them fully.