I have never had problems with the pick not clearing the string above it, etc… I do use some ‘pickslanting’ but I think it’s just a natural occurrence of the guitar being not held perfectly perpendicular to the floor. I hold it like Malmsteen in the Reh video (probably we all do that, I dunno) because holding it perpendicularly would risk to drop the guitar forward, so no one does that, probably.
If I hold the guitar perfectly perpendicularly, I don’t get any problems, because my pick movements are very small, they never touch other strings unintentionally anyways.
But still learning useful things from Troy. This is going to be my last ever study in guitar technique forever. I had done it years ago through other method books and they worked very well for me, I got alternate picking and sweeps pretty soon under my belt, but still wanted to examine the Troy system. Seems all very good.