I know for a fact that dungeon scaling is a headache for the developers. It has to be. The variability of party types combined with the flexible nature of party sizes means that most dungeon crawls present an overly mercurial situation where dungeon parameters need to be adjusted on the fly. I'd like to offer you some solutions:
1. Remove dungeon scaling based on class. That orc's HP shouldn't go up simply because a sorcerer has more DPS than a ranger. Game-wise that makes no sense, and mechanics-wise it makes even less. Don't try to class balance here. What's the point in having more DPS if it is going to be negated by scaling?
2. Scale the dungeon based upon the party's largest size since the adventure began. This means if you're running a 6-man VON3 and everyone drops but you, you might have a difficult time, but it keeps things simple.
3. Make scaling flexible. That means scaling might increase some mob's HP in some instances, and it might increase the amount of mobs in another.
4. Allow the party leader to modify scaling upward. This means if a group wants a challenge, they can max the scaling out if they wish. It's a fun option, and I know a few people who would love it.
5. SIMPLIFY. SIMPLIFY. SIMPLIFY. Scaling should not be an arcane sequence of numbers. It should be straightforward and non server intensive.
I hope my ideas help you make DDO a better game, because while I have been disenfranchised with your choices as of late, I am hopeful that you will right the ship and make DDO the game I used to know and love.