I responded to you in the AltarBoy thread, however, I'm going to put this here as well for posterity and so others have easy access to the information. I may very well be wrong, but I believe this is the first thread dedicated to the topic in quite some time.
A big part of the reason why the Priest healing CC's have lagged behind the others are the group dependency on Prayer of Healing. Honorbuddy does not currently return the specific group membership in a Raid as far as Group 1, Group 2, Group 3, Group 4 and Group 5. For the Holy Priest CC (UPrCCBT) developed by panYama and Gilderoy, he uses a series of LUA calls to return this information, however this is cumbersome and can potentially cause sluggish behavior. There's basically two ways to do this look-up.
- Prior to or when entering combat, which may not return accurate group membership information if someone is moved to a different group after the function runs.
- During combat as the behavior tree runs, which will likely cause an extreme amount of sluggishness and significance decrease in performance and responsiveness.
I would have to go audit the code, but I'm pretty sure UPrCCBT uses some implementation of the former of the two (which is likely the better of the two).
As far as the shielding that imdasandman mentioned, this also is quite a challenge though I have quite a few ideas on how to implement this to model human behavior. Roll Power Word: Shield on the tank(s)/friendly's with aggro, boss-specific behaviors by monitoring the casting of the boss and using Power Word: Barrier before hard-hitting casts complete. The latter of these two could conceivably take a huge amount of logic (and perhaps more importantly, time) to accurately model, but it's not necessarily difficult.
Make sense?