Nah players shouldnt have to grind anything extra for the vault , it should simply be very smart , like raidbots smart . You might get the small upgrade but you won’t ever get 100% all trash.
Your extra stygia can be used to raise all your class conduit slowly by buying
And add 5 sockets to your gear if it did not roll any . Nah loot needs to be fixed a little but not by adding us sinks or making us farm extra or forcing those who hate the maw , to farm there 
edit: from someone doing all content , even pets , i just try to think of everyone without going back to BFA loot rainstorms 