As I understand it; the speed-pedelecs are defined as "mopeds"; and are cathegorized as sutch. Just as cars, motorcycles, tractors etc.
So even when downgrading the motor to a 250w ; the bike itself would remain in its original defined cathegory :-(
Bosch , and probably the other manufacurers of ebike-engines have done measures now to make it impossible or harder to tune their engines. All because of EU-directives.
I do not know if the updated restrictions only are software-based or/ and hardwared-based.
Have any of you tested...