Legendary-eligible event tracker?
 

Does anyone know of an Addon that counts or otherwise tracks the number of "Legendary-Eligible" things your character has done since you got your last legendary?

Things it would count would be stuff like (opening emissary chests, dungeon and raid boss kills, M+ completions, battlegrounds & arenas, etc.) Anything that could potentially result in you getting a legendary to drop.

Maybe this would be a good update to the (already great) SavedInstances addon?

I probably don't really want to know what this addon might tell me, but it would be a cool conversation piece in gchat at least.

Blizz has been very tight with this info, and the lack of its availability prevents such an addon

Really? I thought that all the sources were well known at this point... I know the actual formula is secret sauce, so of course no addon could provide a % chance or anything like that.

They basically told us that pretty much anything can drop legendary loot, but that percentage goes up with difficulty. % chances are not revealed, nor are the bad luck protection numbers.