Multiple actions per one keybind.
 

I'm curious how can it be done.

I slightly understand the concept of ui action layers and that within the layer the keybinds have to be unique.

But is it possible to add new (modify existing) layer to add another action to the same keybind?

Let's say i have 'Shift' bound to sprint action. Can i bind 'Shift' to something else, while keeping it bound to sprint, in such a way that both actions (SPECIAL_MOVE_SPRINT) and my custom action would fire simultaneously on Shift key press?

Thank you in advance.

I don't think this is possible as it would allow a "kind of bot-playing"1 Most of the funcitons are private and changing the keybinds for ingame fight/non-fight "actions" shouldn't be possible imo.

Hm, but we already have multiple different action bound to the same key as long as they are in the different contexts (General and Notifications, as an example).

What i don't understand is how the action layer becomes active? What happens if both General and Notifcation layers are active at the same time? Or there're some limitations (to prevent automation) and you can't make 2 layers with the same keybind active at the same time?

As an author you specify the layer for a keybind in your Binding.xml.
There you can say allowFallthrough="false/true":
...
<Layer name="SI_KEYBINDINGS_LAYER_SIEGE" allowFallthrough="false">
...
If you push/active a layer, it either replaces the keybinding or the Keybind-Dialog would say "Hey, you are replacing the key assigned to action XYZ".
So, you can assign a key to two layers, if the keybinds are not both active at the same time.