Well the way I was talking about was having each frame have its own event.
But if I do that then each handler has to check the powertype. So I could have PlayerPower and Demonic Fury coming in. Demonic fury event is going to get fired off for both player power. So PlayerPower has to make sure its not demonicfury. So you end up calling PlayerPower for nothing.
Also I found that RegisterUnitEvent can only take up two 2 units.
Edit: Decided to go with each frame having its own event. I made a ton of changes to my mod. And doing this actually made some things easier.
Actually, even if you have to check the power type, simply registering by units is a big gain. Imagine what happens with the old scheme with a 40-man raid : all 40 frames receive the events for 40 units...