Duty Roulette: Leveling

[Cnidarian]

This is incorrect. Your experience gets synced to the level you get synced to. So running the dungeon synced to level 20 would give you the same % of a level as if you were level 20.
Your experience and level get unsynced when the dungeon is over. So the experience gained is multiplied. 150k experience at level 20 is equivalent to 600k+ at level 50.

That isn't how level sync works at all. Your required exp to level remains the same. If you are level 59 and you get level synced to 20, you still require 3,888,000 exp to obtain level 60, not 56,600 (exp required for 21). If what you think was true, people would only run Sastasha to level as you can pretty much get a full level every time you run it.