I’ve been wondering this too. I’m a pretty average size but a buddy of mine who has his eye on a Slate is 6’4” and I was wondering if he’d fit.
The legroom in the Ford Maverick is 42.8”. Being that Slate’s wheelbase is like 12” shorter, but not all is lost in legroom. Also there’s no conventional ICE engine up front so the designers likely took some liberties for more real estate in the cabin. That said my guess is Slate has ~ 40” legroom up front.