It depends on the model year/battery size. That was a US only implementation and as you know there is a work around. The other European feature that should be available in the USA is the ability to set when the REX starts to kick in.
The USA requires the REX to kick in at 6% charge. The problem at that level is that the battery can't compensate during short high power drawls. There is a cheat code that enables the REX to kick in a 25% charge remaining. This seems to provide more on demand amperage but I'm not sure what is happening. Hills and wind have a larger effect on speed when off the REX. The REX is just a tiny motor that maintains the battery level but doesn't connect directly to the electric drive train.
The USA requires the REX to kick in at 6% charge. The problem at that level is that the battery can't compensate during short high power drawls. There is a cheat code that enables the REX to kick in a 25% charge remaining. This seems to provide more on demand amperage but I'm not sure what is happening. Hills and wind have a larger effect on speed when off the REX. The REX is just a tiny motor that maintains the battery level but doesn't connect directly to the electric drive train.