While I was cleaning my kitchen I thought some more about this.
1. The resting squat and Bowman's squat must be two parts of a full range of squatting motion.
2. Working in a squatting position (even the resting one) is going to stretch and strengthen your glutes and hip flexors because you have to lean forward or sit more upright to work. You can't stay curled in on yourself. You can't use your hands to keep your body leaning on your knees. I definitely feel stretch in my hip flexors when I squat to chop veggies on the floor, and my tailbone stretches back and lifts up when I sweep or lean forward to chop. I must be moving more towards Bowman's squat when I do these things.
3. Doing Bowman's squat is an important step in gaining full range of squatting motion.
4. But if you cannot do Bowman's squat (as an everyday "working" squat vs. as a PT type posture corrective exercise with props), could it be acceptable to start working in a resting squat to increase your range of motion? It probably depends on if you can squat without tucking your tailbone in, or not.
5. But, I could not squat without tucking my tailbone in right after I gave birth. (In fact, taht is why I did not squat duing pregnancy. I could feel that the tailbone tucked squat was putting pressure on my pelvic organs.) I only became able to squat (in the resting squat) with my tailbone up and down, after doing loadbearing squats. At first, with my tailbone tucked, if I was carrying a load (or even not carrying a load), I felt as though I would topple over. So I would only stay down a moment. Then, as my glutes increased in strength, I stopped falling over. And my tailbone began to untuck. My "proper" squat depth increased. My guess is this must be the more "dangerous" method of increasing range of motion vs Bowman's squat. Hmmm. I will assume that I got lucky or that I was inadvertently doing something correctly, but don't know what it is.
6. Is squatting in a resting squat preferable to sitting in a chair? It must be preferable to slouching on the sacrum. But if you can only squat with the tailbone tucked and the whole spine curled, it must not be preferable to sitting properly, with the tailbone pulled back correctly.