Keep in mind that we haven’t been super clear on what we meant by these terms, because we were still figuring things out. As a good example, what you’re seeing in this clip is actually supinated, even though I would have probably called it pronated as recently as last year:
Yes, anatomically speaking, this approach is “more pronated” than what someone like, say, Steve Morse does. But it is still actually supinated with respect to the strings, which is the only thing that matters for the picking motions themselves. In fact, if you put the guitar on your lap and assume this exact same setup, you will in fact be very pronated anatomically, but still supinated with respect to the strings.
So… can you be “pronated with respect to the strings” and still be a downward pickslanter, i.e. make pickstrokes where the downstrokes are trapped and the upstrokes escape? Yes. But as @blueberrypie points out I can’t think of anyone who plays this way.
…unless of course we’re wrong and there’s someone who is a downward pickslanter, plays mostly upstroke escape type lines, and is actually doing it with a 10-0 motion path and we just never noticed it before, and even if that players is or has been me on occasion!
10 to 0, more or less. It sounds like you have watched that lesson. Recall that Molly and David are 1003. Again, approximately, but just to get the concept, that’s what they’d be doing. Just the downward pickslanting half of their motion would be 10-0.
Edit: If you think you are doing this, by all means post a clip and we’ll check it out. If it’s a thing that exists, and people do it, we should know that, and we should also be more familiar with what it looks like so we’ll recognize it when we see it again.