@mdione
The kits certainly bring some future proofness because you can always simply remove them in the worst case.

The batteries on the kits are likely still an proprietary mess, but the bottom of this article brings up a possible emerging sustainable solution (the #infiniteBattery):

https://www.ifixit.com/News/101675/bike-manufacturers-are-making-bikes-less-repairable

I would look for a kit that can use the Infinite Battery.
@hembrow