I think if the 50/50 rule is creating this much anxiety for you then I wouldn't follow it that closely. For me I'm treating draw a box more for the principles of what is being taught and kind of treating everything else as like suggestions. I think its important to always relate what you learn back to what it was that attracted you to drawing in the first place. I think this rant is bring to light your own process of doing things, which I think is great. If you enjoy working from reference, then work from reference. If you find it frustrating to draw from your head, then keep it to a minimum. So instead of 50/50 it could be like 80/20 or whatever. In my opinion, I think the rule is meant more for concept artists/industrial designers as they are the ones who have to make things that don't exist.

When you said :

" The same page also encourages to draw what I want to draw when I get the skills to do it well. But the thing I'm most interested in BY FAR, is drawing and hopefully, eventually painting people - portraits and figures - specifically and very deliberately from life and photo reference. But that use of reference is wrong, so again, too bad I guess."

I actually think the 50/50 rule contradicts your main goal. Atelier schools draw/paint from life/references (master studies) all day every day. So its definitely not a wrong way to study. In fact, that's the traditional way of studying art. I think this is a case of trying to fit a square peg in a round hole. I think the rule is meant for an artist to be able to retain information better so that when they go to concept something, they can refer back to their memory and frankenstein something together to make something new. That also doesn't mean that going through draw a box wouldn't be helpful. There are definitely good things you can take away from doing this program.

I wouldn't dismiss the rule completely because even fine artists who work from reference most of the time will still draw from their head when doing rough thumbnails during the planning stage. Of course that would depend on what they were making. I think a good example is Alex Ross. He'll do thumbnails from his head, but when he gets to the final image, he'll get reference for everything, the models, costume, lighting, props, etc. There is a video of him talking about his process and he said something like when he was still in school, he saw that all the info he needed was in the reference he took and that he didn't see the point of making something up from his head and he just stuck with that process. It's a good way to see if something works or not very quickly without wasting too much time.

You mentioned that you would rather look at other resources or do something you find more fun. I don't know how you plan on pursuing your art education, but the way I'm doing it, I'm almost treating it like if I was in school. So like one day I do draw a box, the next day I go to new masters academy, another day I go through an anatomy book, another day I do a study from a comic book I think is cool, and one day I don't even draw all and just look at art I like. Then the following week, I do it all over again. You don't have to put all of you energy into draw a box. You could devote maybe 5 days out of the week to drawing/painting figures/portraits from life or reference and then maybe on the weekend do a draw a box exercise. Of course it would take you a while to finish the whole program, but at least you are moving towards your real goal. Definitely switch it up however you see fit.

I think the biggest disadvantage that I've seen from only being able to draw from reference is that it can stop people from drawing at all if they don't have the right reference. It can cause inaction and even cause demotivation because they really wanted to draw/paint this thing but they can't because it isn't in front of them. With all that said, I think the worst thing that can happen is that going through this will cause you to quit art all together. So I would take it easy with the whole rule thing, switch up your studying, and to make sure to draw what you actually enjoy that way you can keep moving forward.