Some day I'll want the electric assist option.
I don't want the mid-drive, which would likely mean a both
a new frame & long engineering development process.
I want something like the Copenhagen wheel, which is
contained entirely (batteries too) within the wheel.
This would be a straight swap out of one wheel,
& it wouldn't compromise the fold.

For something which wouldn't require any development
by Helix, the Rubee might work well for occasional
use.
Who wants what?

Ref...
https://www.superpedestrian.com/en/tech
https://newatlas.com/rubbee-x/52228/