- Multiple controllers for local multiplayer don't really work as there are bugs between GZDoom and Steam Input.
- You need to have set the primary controller as player one as all the other players input will cause the inputs to loop sometimes. For example if you are docking the Steam Deck and want to use an external controller, set that controller as player 1 via Steam Input and not the Steam Deck.
- Pressing "Save configuration" within the GZDOOM options menu and you have mods that adds extra controls will wipe those extra controls. It is better just to set the inputs without pressing save as they still will be saved.
Many mods have also more inputs then what is bind-able on a controller, `L1`, `L2`, `Dpad - Up`, `Dpad - Down` are mostly free for those types of actions.
Try to bind `L1`, `L2` to more action orientated things you need to use more often. While `Dpad - Up`, `Dpad - Down` for things you use less often like Extra Menus.
If it is a new movement type that can replace quick turn try to bind it on `R3` and replace Quick Turn or either of the `L1` or `L2`.
You are also free to change any of the Default binds shipped by RetroDECK and if you mess something up you can always reset GZDoom via the Configurator.