Very late reply here but that's good to hear! Any more updates?
Yeah! I've made some strides in terms of balance, efficiency of change of direction mechanics, breathing mechanics, body awareness. My APT and especially upper cross have improved. I've had a lot of breakthroughs in my understanding of the body. Still though, my body reverts to previous mechanics habits.
I think one issue is I'm still applying the concepts as if I can have perfect mechanics, but because of my torn PCL I actually have to make manual adjustments and arrive at a modified posture that addresses this glaring instability. I can't keep shooting for the "perfect" mechanics because this instability will not be addressed in that case. Just how much adjustments have to be made and what the end result might look like remains to be seen.
I want to post some details but will hold off until I feel like I've addressed all the main parts and my mechanics cease to degenerate back to apt and upper cross and I think the result is sustainable. I'm pretty optimistic that it's possible but so far knowledge has come easily and the progression of knowledge has felt linear. I might arrive at mechanical issues I don't understand and theories I come up with won't address. My opinion is kinetic chains may get pretty complex, especially when one leg has one set of optimal mechanics and the other leg has a different set. And in the end some of the stuff I come up with might only be true for me personally, because of my particular history with bad posture and "weight room athleticism". But hopefully some helpful stuff comes out of this process because I have put a lot of time into it.
But yeah i also don't have any formal training in this stuff so who the hell even knows.