Head Position in Headstand

I am able to hold a yoga tripod headstand and forearm headstand so I thought that meant I was passed these elements but when I got to HS/PE4 I thought, " Am I missing something about tightening muscles?" . I feel in the yoga method I am really balancing on stacked joints and I am wondering if H1/PE1-3 are the same concept, like just about balance? Also, in yoga I was warned to never put my neck in the position that is shown on the H1-3 elements, and I am not saying that they are wrong of yoga is right, but I am curious if I need to learn them with the different head position if I already have the balance for 5 sets of 60 seconds? I noticed on the video for H1/PE3 the headstand is somewhat leaning, and I'm certain that takes more muscle than it does sheer joint stacking balance, so what should I do? 

Thank you so much for your input,

Allison

I like to tuck my chin a little as it feels more comfortable. The main point of these is to get some upside down time. Everyone will be slightly different but should have no neck pain during these exercises.

If in doubt post a video your form.