yeah, an instant loss in acceleration would certainly make you eat pavement in many cases. definitely a fair concern. I might claim that "I hit a rock slightly larger than that small rock I can usually roll over and now I'm in an impromptu pole-vault competition" is a more common issue with small scooter wheels than random power losses, but there's more
personal control over that. (personally: crossing train tracks were my #1 fear and #1 fall cause on scooters)
either way, safety gear safety gear safety gear. especially since basically all these electric personal mobility enhancing whatsits are horrifyingly injury-prone compared to anything the size of a bike or larger.