Mythic + Keystone
I went with a group to BRH mythic +2, all obviously have the keystone for it. And in the end only the person that slapped his keystone at the start to activate it gets to upgrade his keystone. Meaning that it boils down to a rush who can slap in their keystone first.
System should just upgrade evryones keystone that fits the dungeon you are doing... Because I don't feel like doing 40 dungeons to upgrade the whole party to +10