I was fitted with my Otticon PONTO only 60 days after surgery and had no problems. My guess is that as the surgery style continues to improve the wait time will continue to go down.
Surgical style has nothing to do with how long a BAHA implant patient has to wait to wear his/her processor.
The waiting period is to allow the titanium rod to calcify into the skull. Calcification basically "cements" the rod into the skull, making it strong enough to hold the processor. No one - doctor or patient - wants to have the rod fall out of the skull because calcification hasn't been achieved.
Docs have different protocols on the waiting period. Some go with 60 days; some go with 90 days. As with many other things, it's doctor's preference.