Thanks Val, really appreciate you taking the time. All good detail. Textbooks are likely right around the corner for DS. So far, he hasn't had any except an Algebra and a Geometry book he bought himself at a used book store.
Reading it here, I'm thinking, oh supporting pictures aren't so bad. But the Algebra book he picked up (can't remember the title) has a ton of full-color fluff in it; so, I get that idea and it is distracting and wasteful and doesn't help engagement that I can see.
I guess that also trumpets the state of things. I had actually imagined it was something more pedagogical on progressions and which topics lead at what levels to what topics. But if cutting through noise is significant, then it's hard to even have a functional dependency discussion.
Personally, I'd be looking for scaled problem solving, clear overviews with theory and related material. I'd most like to see a flowchart to see the how/why/what behind topics and sequence. But that would be for me, DS has his own instincts and seeks out material of all forms; I'm not certain I'll ever have much curricular input on what he does.
