Drove it for the first time since Friday.
Drove something with 3 pedals and 5 liters more displacement than the GTI for the weekend.
Had some mythological TSB performed on the Throttle body harness. Then about two months later the problem returned and they replaced the Throttle Body. Then a few months later it returned again and they kept it for three days and couldn't replicate it.
That last time I had to clear the faults to be able to drive it but I provided a VCDS log of the faults. They still said they couldn't verify anything unless it was actively logged in the car.
So I'll just keep clearing the faults and keep VCDS handy in the car.