Yeah, a little late to this thread.......
As Tomer points out, tapping down the rinds will help keep the rinds thinner without hampering the action of the penicillin. Additionally, if you are inoculating your milk directly with the penicillin and geo try reducing the amount you use. You can also bring your aging temp down a bit to slow the penicillin growth.
It's a juggling act to find the best methods and environment depending on your particular situation - make some test batches and, as always, take good documentation.