I get the idea of the vault being closed so the team can run through several and that is nice both on how smooth it goes and the speed is sure on faster.
But why not do it with the Infernal Machines aswell?
Just a though!
i dont remember exactly when, but i do remember seeing a blue post about this some time ago. seems like it is on their radar, but i'm not too sure if any updates have been given recently on the idea.