My 2020 Mustang GT has the MT82-D4 and the twin disc clutch (stock). This car is a big improvement over my previous car which was a 2015. Current car also has the FP performance pack install last year at around 8,000 miles. Never any shifting issues at high rpms and this overall no issues...
Had a Getrag in all the following cars with no issues...5 spd in my '89 Porsche 930 turbo cab, a 6 spd in the 94 Supra Twinturbo, 6spd in '15 Mustang GT and another 6 spd in my current 2020 Mustang GT. The transmission (and clutch) is definitely improved in 2020 vs the 2015. Very smooth...