Jerking temp related
On my 30d the judder seems to be related to engine temp. I find that judder may occur when the engine temp needle started registering increased temp and up to about 75-80 degrees C.
And yes, I posted earlier on possible solution with software update. Unfortunately the software did not solve my problem completely. The judder is still there, just less violent, and for sure less frequent.
I'll be talking to my service rep. Don't expect much from them though.