Steam Deck: Controller Layout not working

What is the reason that you are changing the steam button mapping instead of binding actions in the game's options menu?

I do not want to map function to key (open map = R4), I want to map the keys to some function (R4 = M).

Or how would you suggest to use mod button F1 with Steam Deck, or shortcut 1 to use fist slot of inventory?

Also, steam controller layout allows more configuration for the keys (short press, long press).

Sorry, when looking into this I came across a game breaking issue with chat on the steam deck. Once this is resolved we will have an official steam deck layout published with support for the L4, L5, R4, R5

Oh thanks! An modifying this layout will overwrite the in-game settings?

The underside buttons can be mapped to mouse right, middle, 4 and 5 in the steam layout and then they will work in-game. But L4 and L5 are bound to chat which is quite broken right now so be careful, maybe rebind them in game. I hope to get this resolved and a proper default steam deck layout early in the week.

A fix for this is ready for the the next hotfix.
There will be an official Steam Deck layout to pick from, have working L4, L5, R4, R5 buttons, and a fix for text chat.

For the best experience when the patch goes out, you will want to reset the controls to default or manually rebind the underside buttons.