Heal targeting is fucked up, so really none of them are working. It's not a routine issue though, it's a targeting issue-- the routines themselves should work fine if that gets fixed.
Would the targeting be a defaultcombat issue or from buddywing itself?
Hopefully this can be fixed at some point, healing has been non-working for quite a long time.
No idea, although I imagine the healingmanager code could be cleaned up significantly. BW had issues with targeting before 4.0 though-- remember all the companion targeting issues? Now it's just everyone AND the companion :/
EDIT: I'll add that I'm willing to share the code I use for my Disc Priest routine in WoW, but I'm not sure how much it'll help since WoW has way more API functions (like being able to tell if someone is a tank, or even in my party).
All you can do is, make contact with aevitas or bossland GmbH.Cryo if there is anything I can do to help.
It is crazy frustrating that Buddywing feels way more broken than not but you, and others here and there, make it almost tolerable. It seems a remote possibility to get some additional programming muscle involved but it sure would be nice to get the constant crashes, lockups and broken features fixed.