Ideas about ways to quick equip AWS parts, skipping the GUI:

1. Shift+rightclick: swaps skin piece between player's body part and mannequin's body part that you shift-rightclicked on. Example: shift-rightclicking mannequin torso will equip player's torso, and vice-versa.
2. Redstone powered mannequin: if the mannequin is redstone powered and the player shift-rightclicks it, all skin pieces are swapped between mannequin and player
3. Dispenser: pretty much like what you can do with the dispenser with vanilla armor.

Redstone is a good idea

Swapping skins with Man. is going to be an issue due to the number of skins a player can have equipped. Also there are commands to force skins to the player, even in specific slots. Imo this is unneeded.

If you feel otherwise, please open a new ticket.