What a nice discussion man, i gotta say it's the one of the most effective drawing exercise thats out there in my opinion. Teaches you how to see rather than look.
A simple suggestion i would give you is you should really take the time to observe what you are going to draw (not like irl that would be little bit creepy) like, talk to yourself; describe what you are seeing to yourself as if you couldnt see it. ''yeah that muscle connects to the brachialis major and it overlaps the forearm and it goes in with this angle'' that way even if you don't remember exactly how it looks, you have a general idea on it.
nice man! can you give me insights on these measurements in the first pic? what does 2,4 same lenght imply
