Bringing back the defeat penalty discussion started in another thread:
It was a 50% penalty for 10% of the XP required to reach the next level.
- With a 200,000 XP requirement it’s 50% of 20,000 or 10,000 XP lost
- With a 2,744,000 XP requirement it’s 50% of 274400, or 137200 XP lost
This means at max level (180 vs. 50) there would be a roughly 14 times increase in experience lost per death. Assuming you clear the penalty each time before you die again 
Hopefully this will just have a hard cap. If not - these guys who like always running the reaper buff will be looking at 5.4m XP per level.