I went around a group of geese as they were blocking the sidewalk. When I went thru the grass my scoot sunk to the deck in mush. I jumped over the front but the scooter stayed upright. I always leave mine on dual motors. Range didn’t “improve” with just one motor, and it was extra slow off the line.
Your son is getting comfy on the scoot and like every young man, we want a bit of extra power. Make sure is helmet is in compliance with e-powered bikes and that he wears it. Me personally, I think sitting on a electric kick scooter would be twitchy. I’m constantly shifting my feet for various terrain changes and I think a seat would limit my reflexes.