Following with interest, too.
I wonder if there's a "dynamic" element, same as with some narrower pants and/or wider boots. The fit of the boot shaft and the width and length of the culotte hem have to work together so that the legs stay over the boots and return there when getting up after sitting. Full knee-high, fitted calf boots should work fine with a variety of styles but I could see some in-between styles that would hang up.
I'm just thinking it's a bit different from a skirt, which easily falls back over boots, and that I find static photos able to show stylings that behave differently in motion. Most culottes I would target would likely have relatively full hems but the straighter, almost cropped-pants ones would work differently.
