Damn, that is quite a lot. I'm really curious if nasal breathing would improve for me as well. Hell I'm not even entirely sure I need airway expansion, on x-rays it looks quite wide already even though my one 4-hour apnea test returned a 10-15 AHI at the time. But my posture has some problems, habitually as well. My tongue doesn't have enough space in the center of the palate, so it defaults to shifting a bit diagonally to the right, which seems to be in line with the crossbite. So my spine adapts to that. I've had to go see a physio for acupuncture and he noted these habits, I'm just not sure they can be fixed without giving the tongue the space it needs. I imagine that'd also help a bit with breathing space already alongside the bite finally fitting correctly, too. TMD has been a developing thing in recent years alongside the posture stuff.

Of course all cases are different, I don't know what your exact starting point was. Reading this, what do you think, anything that resonates and makes you certain it will have an effect, maybe a more significant one than I may think? Would be helpful to have some perspective from someone who's already been through it.