I've been working in the Foundations curriculum for a while now and it seems to me like I do better going through a class, spending some time working on the assignments and then, moving on to the next class where I'll inevitably come back to the previous classes prompts to adjust or try again with new energy
I feel like I'll be going over the foundational concepts for years to come (which is good with me!)
Just lean in to whatever method of learning that works best for you and +1 to the others here who note to avoid the perfectionism trap!!