To your original question, some that have had the TSB applied said it helped and others said it didn't. There's a software update and new driveline (4WD models) that comes with the TSB. If you live in a colder weather climate and have 4WD, the driveline update should make a difference. The new driveline comes with a softer damper around the carrier bearing, which especially when cold, does a more effective job of absorbing driveline vibrations.
As far as turning off VCM, have you looked into S-VCM? It does not alter the coolant reading on the dash and keeps VCM turned off no matter what the driving conditions are. I installed one awhile ago and it works as advertised.
I am using the S-VCM controller as well and I did notice a slight drop in the reading when it is in "normal" operating condition, but the reading hasn't varied that I've noticed. Once the heat range gets past a certain parameter the S-VCM will remove itself from the signal path and you will receive and "actual" heat value. Otherwise, the just-slightly-below-normal reading is due to the resistor.