I don't mean to be negative about the guy, I'm just curious really.
While doing my UKSCA stuff I spent time with sports scientist, and it really isn't a strong indicator of anything. I've also read someone's masters thesis and was full of Bertstare.
Ankles shouldn't be completely vertical when deadlifting, but I'll reserve judgement.
The problem with the orthotics is the position they put you in is completely passive for the foot and lower leg supporting muscles. Yes, they do put you in a better position and they can temporarily remove some of the upstream problems, but that is gone as soon as you take them off.
I can vouch for this: I did most of a Sports Science BSc (double honours with Materials Science... basically means I didn't do the dissertation) and I can confirm a Bachelor's degree in it means you know how to do the zip up on your university tracksuit, and make sure your trainers are really, really white.