I will admit that it definitely is worrying when students come back this quickly. Your work is for the most part fine, but in general remember that there's more to absorbing and processing feedback than just jumping back in and drawing. The time in between, that negative space, also contributes to how our brains go over what has been explained, as does the time committed to rereading feedback, going back over lesson material, etc.

Anyway, you're definitely demonstrating much more care when it comes to observing your references, and your proportions are notably more realistic as a result. You've also continued to develop your understanding of how to shape the additional masses, and push how they wrap around the existing structures.

I do agree that head construction is still something you're struggling with, and it always comes back to applying the principles shared in the head construction explanation on the informal demos page. As shown here, you're still deviating from that approach in some ways, which suggests to me that while you've read through it, you're not necessarily specifically trying to apply it to your constructions, but rather are trying to apply its general idea. Think of it as a repeatable technique you can use.

Also, try to start with smaller cranial balls - you may find it makes things easier.

Anyway, I'll go ahead and mark this lesson as complete.