Good advice and I did it.
Why don't you try putting the shifter in manual mode when in 6th gear, then at 60 MPH do your acceleration process and see what it feels like to get to 70 MPH. I'm thinking the change is in the transmission flash, not in engine capability (torque/power).
Let us know what your impression is after trying this change.
I got the car up to around 60 mph and put my DSG tranny into manual mode. I stepped down on the accelerator and a VERY slow acceleration to 70 mph. This car is NOT the SAME CAR I brought into to get the phase 2 done. I am disappointed to say the least. I drove the 1.4 gas jetta last summer and my car acts like a small engined gas car where all the power comes from revving the engine up. This is not the way my 2009, 2012, and 2015 were! They had gobs of TORQUE.
I took it back to my VW service dept. Service advisor said they've done all they can do with it. Said they hooked my car up to a computer online and they reprogrammed my cars computer. Well they also put some hardware on it, and because of a CEL regarding adblue they replaced that hardware and later the adblue injector to turn the CEL off. Maybe this is a factor?
On a side note, I have averaged 41-43 mpg in suburban driving for 14,000 miles using fuelly software. My first tankful was 35 mpg and my second tankful was 39 mpg.
I am going to start making calls and writing emails to try to get my car straightened out. I have owned and driven 18 diesel VW's for 34 years. I would like to get the performance back for my Jetta I've owned for a year.