I also noticed the power reduction below 20% battery level. On the one hand, this is quite early, but on the other hand, it is a good protection for 1P range extenders so as not to trigger the BMS too early.I did another run today. 35km, 1060m of elevation. Some of it was on boost, majority, in sport and eco on the flats. Came home with 12% battery left. Motor for sure has a lot of power. For me, more than enough. In boost is is very rapid. But the battery from 30% to 20% was drained very quickly. And below 20% you are getting only cca 120w max, regardless of the power mode.
Bike also handles well. Additional weight on the downs is quickly forgotten.