at those speeds you could turn var diff off, there is no advantage, this will give you diff1 work on all the rigs on your GLOBAL worker
Might be a good time for a reminder that VarDiff is designed for fast hardware, currently mini rigs soon asics
I have 15GH/s more coming this week.
and if you want you can check my username on Ozcoin to see the GH/s I have and my Ozcoin username is "betatest512"
So can you please try to make Dynamic VarDiff work separately for each authentication.(Try talking to Blaksmith about this)