I would call Richards Recreation in KY and talk with Mr. HP (Eric) or 222 (Randall). One of these guys could answer your question. I haven't heard of any issues with the stock CDI and the "gear crunch" sound. My understanding is the advance timing on some CDI's at low RPM cause this issue. Do you have a friend with a DS who you could loan his stock CDI to see if you still have the problem?

The result of this over time is a trashed "sprang clutch". $400 if you do the work yourself. I believe I read somewhere that the part(s) can be purchased cheaper from a BMW cycle dealer.

 

Great.
Mine is stock. I am a firm believer in "If it ain't broke, don't fix it."
Is this something that should be addressed before additional damage occurs? Or is it an isolated problem waiting to happen?