Oh, I realized why all around the junction of my legs with waist was sore yesterday: I’m now at the point my legs are recovered enough to start operating with knees bent squatting, which was earlier a position I could move through but not retain stability in.
This clears up all remaining timing issues and hinkiness in my step, which I now realize was a matter of gathering up to push myself through one of those through-not-in arcs.
The soreness is at least “this is getting more capable and will handle this level of strain fine in the future” ache, it’s really most noticeable waking up in bed and is muted when I get back upright and gravity starts compressing tissue along the axis of my spine again