I did the same with Bosch. The Bosch gen 4 chips do "compensating" in the end. So the average speed and usage visible during service is "normal". I serviced the Bosch gen 4 bike and never did I have any problems. I don't know what kind of shenanigans VOLSpeed does to trick the Giant Yamaha motor though. So going to the Giant service maybe will be the part of the "long term" review

.
But... As far as I know the speed that is registered by the motor is nowhere close to what WE see. The information that goes to Giant Ride control app or Garmin or whatever doesn't come from the motor. There is a Bluetooth unit outside the motor ('ve seen it with mi own eys). So my guestimation is that the motor sees "good" speed and the "real" speed is what's sent further. But I will be more than happy to listen to someone who really knows how it all works has to say.
I will take the risk because I honestly don't care that much. This rare smile on my face is much more important to me

. And I hope that community will profit too

. BTW. The maker of VOLSpeed told me that they tested the system for more than 1200km now. Works. They are quite popular here in Germany so I decided to add a bit of trust to my calculation if I want to install this thing or not.