Your longer time limit studies generally capture the subject, however for the 30 seconds to 1 minutes attempts, I'd suggest adding flesh to them when you've mastered the time limit. Specifically, for the torso the part where the ribcage ends is often a pinch or a stretch depending on the pose. This is an important visual indicator for the pose. You've done it for the studies, so a simplified version would work for the quicker attempts.
For the limbs, I noticed in a couple of instances where the knee region is thicker than the thigh whereas it should be generally reversed. Sometimes the time limit or pose may cause this to happen, but again, simplifying the form and knowing in advance the general shape will prevent this.
Hope that helps!