Yeah, my suggestion would only fix the disparity between m+ and raid myth track loot.
Vault would be less important then.
The reason why vault rng is so bad, is because that’s your only chance and if it is bad, then you are done for the week.
If that would just be one of the many rng chances, then it would feel significantly less terrible to have a bad vault.
The real solution would be some kind of deterministic loot, but that is something blizzard would probably never allow.
They are sweating blood even with this raid dinar system so I can only imagine the tragedies such a system would cause.