WowAce

Blizzard default raidframes can have the same debuff shown multiple times, like several fixates from the same mob type. For example, in Motherlode: The bossadds (Earthrager --> Raging Gaze) fixates random people, and you can see when you are fixated, but not if you are fixated by more than one mob. This would be handy to, instead of seeing additional icons, like in the Blizzard frames, which would be really messy and cluttered, you could show the same icon with a stacking-number instead indicating the number of same actual debuffs on the same person. Then you would know that you are targeted by more than one mob.

Or the Feral Bloodswarmers in the Underrot with their Thirst For Blood fixates. If you are fixated by more than one in higher mythic keys, you'd be dead if they hit you.

You have the Spit debuff from the Devouring Maggots in Waycrest Manor. Seeing how many of the actual debuff you got would help alot to healspam that person, instead of just seeing one when he/she could have 3-4 dots, but you won't see it.

There are probably many more examples, but I gave you a few so you can see what I mean. Thank you.

Sorry, An important  aura code refactoring would be needed to implement this, declined for now.