It'd be really nice to have the ability to scroll the action bar using a keyboard shortcut, or to have the ability to assign a custom shortcut key to this action. It's one of the few things for which I have yet to find a keyboard equivalent. I asked in the Discord and was told this isn't currently possible, so I wanted to open an official request here.
If there's a way to somehow script this client side without any changes, please also let me know (even if it takes multiple keystrokes). I know there's a scripting system but I'm not sure how exposed that is to the end users (I haven't seen much in the way of documentation).