I would love an option to apply debuff highlighting to the frame border (like Xperl) rather than highlighting the entire frame. Highlighting the entire frame makes the health bar harder to see for me, and turning it off isn't a good solution for me either, because I know I'll miss the debuffs if I do. This is one feature of Xperl I sorely miss since I switched, but I greatly prefer the "look and feel" of ag_UF, so I don't really want to switch back. ;)
Sorry if this has been addressed already, search only turned up one similar thread.