Pump time for glasswork 2

I almost always pump for at least 5 minutes between flushes when I'm doing glasswork.

Pump time for glasswork

When doing glasswork, how long do you wait for each pump of the pump/flush cycle? I used to wait almost no time at all, but now I'm thinking I should wait at least 5 minutes. This is because when using the mini-antechamber of the glovebox in 291, a 5 minute wait is necessary for each cycle or else oxygen will be let in.