UPDATE: So in the end the noise I was hearing at idle is completely normal after having a 3rd opinion from another Porsche Tech. I also listened to 2 other 996TT and they were actually a bit louder at idle (these were stock clutches btw). The tech said mine was actually on the quite side So it looks like I was just worrying to much after all the work & money spent. Just turned 40,000 miles this week so time to just enjoy my car.

 

Update on the Update: I just got my car back last Friday 15th after a 2nd rebuild and I am happy to report my transmission at idle with the clutch in or out makes NO chatter/noise any-longer so what I was hearing was not normal after all. I have zero whining noises on deceleration from 2nd to 1st gear. Just wanted to update this thread if anyone in the future encounters this issue on a rebuild.

 

I get chatter

it is normal and to be expected