About Bellybutton: Sorry for direct the direct translation from Swedish to English do not take it literary
I have SS 2nd edition. I know what hip drive is, I know that high bar squats moves the tension away from PC to the quads and that a low bar squat engages the PC much better.
I also know that the squats I posted for a couple a months ago sucked(knees going forward taking tensions of pc) and that I have been working with page 47 in SS for several weeks without success trying to improve this.
The squat setup that my pl coach had me use is looking a lot like the squat the guys at EliteFTS.com teaches in the series "So You Think You Can Squat"
Now I am moving more kg and feel that I am actually using my PC(I did not feel that before)
I will have to come back to you about the "angles". Seems It just made a lot of confusion by writing those to words.
I will take your magic book to the pl gym the next time I go there and show it to much coach and let him explain the "angles" vs low bar squat.