What I had in mind was a cutom window with 30 text objects. On clock toggle, just dump the raw tooltip value of every maintained ability into the corisponding text object. No need to scan for specific targets or abilities. With the right sizing, it should be possible to align the tooltip strip with the buffs.
Actually I think I'm gonna implement this for my UI as an optional file
I've not wanted to add too much of the Maintained DD stuff in and force users to a vertical maintained layout, but implementing it as a seperate window should be flexable enough.