> then you’d have to deal with the ethical and legal issues of where it lands

Meh, it's a risk reduction thing. Aircraft sometimes dump fuel too in emergencies: https://en.wikipedia.org/wiki/Fuel_dumping

Earth is covered with a lot of water too, if you could eject it... risk is approaching zero on dumping a flaming battery over ocean.

dumped fuel does not land on the ground, it evaporates