It's not always easy to tell if a car is remapped when driven sensibly, believe it or not the majority of mechanics are very respectful of other people's property and won't give a car the beans unless it is specifically required for testing purposes... add to that we are living in the age of dash cameras and tracking devices most would rather keep their job than go for a joyride.
As for the "numbers" don't dwell on them too much. Variations from dyno to dyno aside a stock Mk7 GTI makes around 300bhp on any of the big name maps. There are Revo maps tailored for manual cars with a less aggressive torque delivery, I honestly couldn't tell you how many I've done, must be 25+ and never had any clutch issues. I've installed Revo maps on even more Golf Rs and I can only think of one that had clutch issues, but he was going stage 2 anyway and an uprated clutch was already on his shopping list.