I do a similar mileage to you and went through the same exactly the same parts as you, with the exception of different brands of coilovers and downpipe.
Because of that mileage, I went back to Stage 1 tune and standard engine mounts, but left the Vibratechnics dogbone and coilovers on. Even the fast road spec Vibratechnics side mounts are too stiff for a daily, and they're rubber! God knows how people live with poly mounts on a daily basis.
I absolutely love how it drives. The coilovers are compliant (Ohlins) and the Vibratechnics dogbone keeps most of the engine movement in check, but it's just so much smoother and quieter compared to the full compliment of VT mounts.
My Helix has been OK for 50K miles luckily, but the pressure plate on that kit is made by Sachs, so not technically the fault of Helix. Helix make their own (billet) pressure plates now, so take from that what you will! The Sachs sporting clutch kit is well known to be very heavy and unreliable, probably why Helix ditched their pressure plates.
One thing I have noticed running a far heavier clutch is the dual mass flywheel doesn't last long. Something to bear in mind a couple of years down the line when it's starts rattling.
On/off the throttle at low loads/road speeds can indeed cause a jolt on these cars, but not a knock specific to that that I've noticed on mine. A drivetrain knock is usually something loose or it's contacting something on the chassis.
