The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
Haven’t seen a particular episode on it, could be something to maybe look into. That is to say in addition to the upper, shoulders & neck posture…
I now think like split snatch, or pistol positions through my day of sitting for the lower portion. I noticed if both feet are out, or both are in, that as time passes I tend to over extend or flex. But when splitting my leg position, my hips and trunk seem to stay pretty neutral. Comfort without a lot of thought, so in addition to the top I only need to remember that one other thing regarding the bottom, that is to split a bit.