I, too, think the un-shuffle solution is far from ideal. As for how to get around the "which playlist" issue, how about just having the player take the current track and use the "Source" and "Track" fields rather than trying to pick a playlist... So it would pull out all the songs from the same source, sort them on track, and there you've got your album. It would probably want to also use the Artist field in case two artists have albums of the same name ("Greatest Hits" being the obvious candidate for worst offender.)

This solution require accurate Source and Track fields, but has the advantage of being very straightforward. It could also be chosen to replace the existing Tweak Order source button, since it would have the same effect, save sorting the tracks, and it would tweak ALL of the tracks from the album instead of just one each time you hit the button.

I'm not saying it's easy to implement, though.