Ok,

Firstly, you sound like a physio, esp if you have Diane Lee's text.

Secondly, outflare/inflare is based on muscular control. You will often find an outflare (PSIS moving laterally relative to the other side) will correct with a good lumbar multifidus contraction.

Thridly, it sounds like something else is driving your lumbopelvic hip problems.

I am not really an advocate of 'unstable' unless you can demonstrate on u/s that a good core contraction still leads to excessive, uncontrolled joint motion. However, having said tht, your hip muscles don't want to let go for some reason. They usually don't act in isolation - what is the co-contracting muscle?? It sounds like TFL is dominating the hip.

Your core stability exercises shouldn't be so difficult. If it is, there is an underlying issue that is unresolved, probably apart from the Wikipedia reference-linkSIJ. Have your thorax checked. The answer may lie there. Also, how do you know if you are doing the exercises right or not? On what evidence are you basing this on?

In general, it sounds like you have a MET background but in my experience, if you have to keep fiddling with correcting your pelvis, you aren't hitting the right buttons - check your diagnosis and consider what other possible areas of dysfunction might be at play. i find that it should only take 1-3 sessions at the most to sort out a pelvic dysfunction - if i have to keep going back to it, i have missed the primary driving factor. If you read Diane Lee's text, you will find that there is not much emphasis on positional diagnoses but rather a functional one.

Where in the world are you from? Also, have you seen Peter O'Sullivan's work on classification of NSLBP??

Thanks - looking forward to more information from you. ACtually, can you please provide a more complete history on what your problems are? Thanks