I'd don't have a 3722 (we have a Spree Escape E204S TT) but my experience with KZ warranty repair was good.
First, the dealer I purchased the TT from was three hours away. KZ worked with a local non-KZ dealer to do the warranty work.
There were some communication stags between KZ and the dealer. If I called KZ I either got through to the individual responsible for my area or they called me back within a day. The biggest communication problem seemed to be between the dealer and KZ with the dealer telling me on more than one occasion that they were waiting to hear back from KZ. I found myself having to play middleman a few times but ultimately the work (repair pumping leak, replacement of insulation damaged due to the leak, trace short in running lights and find/fix bad connection in one stereo speaker) got approved and completed.
I would not wait weeks to get a response back from KZ. Call and follow-up. The dealer documents the issues and sends it to KZ. They will review the list and send the approval to do the work to the dealer. It probably took 3 ~ 4 weeks to get the warranty work approved and completed.