We had the issue about people wanting to always 3 chest everything, instead of going for higher mythic+.
What if the loot system gave u ONE CHEST in each mythic+ done IN TIME, regardless of how fast the group went, its always one chest with a 100% loot in it, instead of 3 chests that may contain no loot.
This would get players back to play higher mythics, according to their ilevel. Wouldnt it?