i don’t understand why people deny that other people use the drop to secure the mouth closed. the drop by virtue of coming closest to the nostril[s] of all modern cavesons, prohibits the degree in which the horse’s jaw can open, which in turn makes for a quieter mouth and draws the illusion of accepting the contact – because the horse cannot gape his mouth to avoid the bit. i have found this is the primary reason people go for the drop. if you want a stable bit, pick a stable bit like a baucher or a d-ring.
by virtue of application, the drop functions by holding the bit upright to the corners of the mouth, instead of allowing the bit to “hang there” by the cheek pieces. it certainly does put the bit in a more stable place, until rein action is applied. the force of a rider’s hand trumps any flimsy piece of leather, and then the bit is only as stable as the person wielding it…
in a professional sense i have seen more than one professional put a younger horse in the drop to hide resistance - this way they can push them forward and show off their gaits without losing the illusion of acceptance to contact.
as a ring steward i’ve seen a few drop nosebands in utility, usually on the younger horses in training level / 1st level, occasionally one or two at an event but not often. in bit checks i have yet to find a drop noseband that was fitted correctly to the horse’s head, which is two fingers width of looseness between the jowls and strap, and between the bridge of nose and strap. i have never been able to fit even a single finger between the bridge of nose and strap in any of the competitors that i bit-checked. often times the drop sat very low and interfered with the nasal cavities.
FWIW, years ago one of my projects had an inconsistent tongue wag that did not show every ride, but seemed to be related to canter work. my trainer suggested i put him in a drop as he would have a harder time pulling his tongue out if the bit was higher in his mouth. i did that but i also called the vet - we x-rayed his front feet and turns out he had incredibly thin soles and the canterwork was hard for him. put pads up front and i never saw that tongue out again…
sometimes it’s worth investigating why they are resisting the contact over slapping on a band-aid noseband.