That’s a considerate thing for you to say as a teacher, and it’s the right philosophy. You don’t necessarily want a student like the one I describe and a teacher like the one I’m asking you to be for the sake of the hypothetical is the kind of teacher (not to mention the kind of parents) who can screw kids up in the long-term beyond depriving them of a normal childhood.
I’m deliberately trying to communicate a very restrictive hypothetical here. This student won’t even pick up a pick unless you tell them to. Think of them (it?) as a learning machine, and you want your learning machine to achieve the greatest accuracy and speed while expending the least effort both in practice time and in execution. If you don’t guide them in a specific direction, they have no direction, and there’s no asking for their opinion on what feels right because they do not know. Program them based purely on mechanics. So, what would you do?
Maybe the latter hypothetical (building the perfect player in a simulation) is easier to grasp. It’s certainly easier to communicate and I could have saved a lot of typing by just presenting it. 
I actually said ‘practically no slant’ because I knew someone would say ‘there’s always some slant’. Also, cutting into the string with the edge of the pick is rotating the pick on a different axis than the sort of slanting towards the ceiling or floor ‘pickslanting’ in our sense refers to. To achieve speed, it certainly helps to cut into the string a bit, you’re right. That’s one of the many variables I’ve deliberately left out of this, however, because I don’t think it’s clear what the ideal angle is and, considering the affect on attack, this takes us into dynamics.
Cross-picking can be done with a neutral middle of the pendulum (versus the Albert Lee slant), so I consider it compatible with the neutral two-way pickslanter I’m talking about–yeah, I’d definitely make sure they master that.
I should add, because you’re such a good teacher and have access to so much funding, you can communicate mechanics clearly without being able to string skip while playing 18 notes per second, and you can fly out the world’s greatest guitarists for in-home demonstrations whenever you want. In other words, while a teacher’s style typically has a great effect on how they teach and what they teach, you don’t have to have chops from another planet and your student isn’t going to mimic your personal style unless you explicitly instruct them to.
Edit: Preemptive response to someone telling me “there is no ideal”: Imagine a person with an artificial brain, but all other parts are biological. Their brain can be programmed by another person, or they can program it themselves instantly writing to ‘muscle memory’ the sort of complex motor routines that take us much repetition and much sleep to retain. They’re effectively a CNC machine with biological servos and pistons. Better learning capabilities than us 100% biological humans, but with the same moving parts. Like a CNC machine in a factory, this cyborg can be programmed to accurately carry out their task as quickly as possible while expending the least energy with the slowest wear on their ‘tooling’.
To make our ideal guitarist a little more flexible while wasting a miniscule amount more energy, I’m overlooking cases like the Paul Gilbert descending sixes thing where, technically, you would be expending less energy by maintaining an upward pick slant the entire time and not going back to neutral in between string changes (since you don’t need downward pickslanting for this lick at all unless you go back up the neck afterward, like in Technical Difficulties). There can be exceptions like that, but I’m trying to speak generally here (this is complicated enough :P) and I don’t think these cases discredit the simple ‘ideal’. Besides, that’s a simple lick and we want our cyborg to focus on monstrous feats to prove their virtuosity as a complicated machine makes absurdly tiny transistors rather than the broomsticks an autolathe could manage.
Now, with real humans, it’s probably impossible to figure out what the true ideal mechanics of alternate picking are. However, I feel like we know enough that we can speculate as to ideal technique, and that’s all I’m asking people to do. A lot of people find such hypotheticals worthless. That’s fine–you need not play along.