[Isamu]

>One caveat is the board can’t engage regenerative braking when it’s fully charged. [...] I’m not sure why the board can’t just continue braking without the regen.

The power generated by braking has to go somewhere. If not to the battery, it would have to be shunted to a big resister array, and wind up as waste heat that might require cooling fins. This would add weight and cost.

I remember riding a metro car with regenerative braking that dumped the power to a resistive array on the roof that made a kind of buzzing noise when braking.