Even this would be great, or if not this if they want a limit on the number of buttons, maybe a pick and choose which buttons you want.
I know, for example, that by default on Poweramp, there's no, I think it's previous track button in the notification, it's play/pause, next and the notification unloading X. You have to turn the option on to have the other button (and it warns you when you do that the notification unloading X moves down into the expanded notification). Something like that I do remember because I just set it up a month or so ago (Got the bike November 30, started messing with audio system in December and that's when I found that option).
Anyway, doesn't necessarily have to be like a long press or double click, could be a whole separate button. Just some way to skip albums from the notification.