TNT / PersonX - I get your point.
What I have realised though is that one must pay close attention to prana to apply the bandhas correctly. So this is what happens with me instinctively:
During SBP - Head is thrown back, I inhale, drawing prana upto the solar plexus, mulabandha kicks in. I am still inhaling past the solar plexus to the throat, uddiyana kicks in pushing prana upwards,head is straight. Inhaling past the throat - tongue rolls to soft pallet,creating a direct path for prana, head start to dip forward. Upon reaching third-eye, head is now in chin-lock, sambhavi is in place (remains in place all the time). During the small pause at the third-eye,I further tweak all the bandhas to 'top up' the upward surge of prana (sometimes I add Navi Kriya). Exhalation, the head comes up, bandhas are released one by one (except sambhavi), head is all the way back by the time I reach muladhara and ready to take the next in-breath.
I repeat - this is
my take on what happens, not exact AYP instructions.
Sey