ebike shop will fit a dongle and honer the warranty but dont sell the above bikes.
how does he do this ill tell you no dealers software can tell if a dongle has been used neither can bosch themselves prove it one way or another if one has been used on a bike or not.
no proof has ever been posted buy bosch or any dealers.EVER
what the dongle does is lift the speed limit so makes the motor sclass that bosch also sell with there software and a higher 45kph speed limit.
as all the motors are 350w all you are doing is using the motor what it was made for in the first place so to refuse warranty because a dongle has been used is just nonsense tbh.
so if you want one keep quiet about it on here ect and you will have no problem.
if a dealer says a dongle has been used then ask for proof in righting cos you will not get it.
if it went to court they would not have a leg to stand on as will have no proof one way or the other.