I've been recently rereading all the material on the website, I've noticed from the post : "make sure you're mewing properly" that the OP contradicts himself. He says to replicate a swallow feeling during a chin-tuck, however at the same time to push against the bony structure and not the soft tissue, yet when I swallow I feel most of the pressure on the soft part way back into the palate and not the bony structure right in front of it.
If I freeze the motion of swallowing at it's muscle tension I feel a lot of tension in the chin-tuck going upwards, but it's impossible to breath then.
So which one are you supposed to do?
I think what he is saying is that, during you swallow you feel the tongue push up on the soft pallet. That is where the tongue should be but you shouldn’t push that hard because you can’t breathe.
Try the swallow and hold the tongue like you did before, now slowly lower the tongue just enough for you to be able to breath.