this is done with many motorbikesThat's what a lot of ebike shop owners and mechanic say, but I never understood.
The classic example is when people install speedbox or something to unlock the 20mph limit, their argument is something like "Yamaha designed this motor to go up to 20mph, not 28mph or 30mph"
But why does it matter? Since it's a mid drive, as long as the cadence (110rpm or whatever) doesn't change, wouldn't that be a same thing?
What if you get a larger chainring? How is that any different from a light person going on flat surface with larger chainring, than a heavy person climbing up hill with smaller chainring?
Also there's a motorcycle called Suzuki TU250x, what a lot of TU250x owners do is to change the front sprocket (equivalent of ebike chainring) to get a better highway cruising capability and wider gear range, to keep the rpm low at top gear, etc.
and sometimes go the other way
with my RSV4 i found the bike geared to high for low speed corners
went down 1 tooth on the front and it was much more manageable low speed
top speed wasn't really affected at over 300 km anyway