This photo is from 7 hours later, after washing it again just in case. It is still quite angry with me. I don't blame it--those trousers are mean! Shea butter is not a cure-all in this case, sadly.
I do think I've found at least a partial solution to the gaping slant pockets: by adjusting the tension on the pocket vs hip facing I've stopped the pants front layer from pulling and sending the pocket opening flaring upward. The hip facing (layer against the skin) needs to be at a slightly higher tension than the pocket (in the center, and this whole assembly is more tensioned than the pants front (self explanatory). This way the upper layer has the least amount of tension while worn, the lower layer the most in case your fashion fabric stretches, and the pocket layer should be completely stable and floating in the middle withtout a care in the world. Which is where I'd like to be.
I've now basted and removed most of the pins, the trousers are just waiting for daylight and someone brave enough to try them on. If the pockets still gape badly I'll give them one more chance and then declaring it as good as it gets. I would consider basting shut the pocket openings but I know I'd be driven slowly mad by having pockets that are entirely inaccessible. So we're not even going there.
*Those pocket bits that extend all the way to CF that you're told are so important but right now are just a pain in my ass.