isn't there a FAST game speed? Something between the medium we have now and Fastest?
Why not do a test run on that speed for a bit. I mean, IT IS a beta. Why not test a different speed and see if that speed hurts what's been done, or helps it. If it's not efficient then roll back to medium.
If you DO do a speed increase, don't tell anyone until afterwords. That way the complaints won't be premeditated. A lot of people complain that faster game will increase spam, so if stated ahead of time, then the spam complaints WILL increase. If not, then the likelihood of them increasing is minimal for the first day or two.
TL;DR
Ninja increase game speed to fast(if it's there, not fastest), test it for a few days and see the results.