From the Ross Tech forum:
"VAG have made significant changes to the firmware in their 2020 and 2021 models, so it will take time for owners to catch up with those changes - VAG don't publish them!
But don't expect any tweak for Start/Stop to become available - VAG have been forced to disable any tweaks that can affect emissions after the 'Dieselgate' affair. The only option, if you have a switch not a soft key for SS, is a memory module which you can find advertised on a well known auction site (and elsewhere)."