Others may have better definitions, but to me, a drop holster is one that positions the holster at some point below belt level. A drop-leg holster is the lowest I've seen, with various methods for hanging the holster low with straps that go around the thigh. The Comp Tac holster I have is more of what I would term an "offset" - it has the part that fits over the belt, but attached to that is the "drop" or "offset" piece to which the holster actually attaches.
Thinking actually feel your need and what you're saying?
Many if not most current holsters are designed belt height for rigidity and simplicity in manufacturing, cost and in many times normal carry possibly concealed by a coat or an untucked shirt. Holsters that deviate from that trend are sometimes very rare.
Holsters are a very personal choice for many reasons, Over the years, have found one size fits all a very huge misnomer.
Personally, am not a Kydex fan. - The sound they make while holstering makes my skin crawl. Would rather use leather or the softer, flexible nylon holsters than Kydex. Plus, the softer holsters don't make scraping sounds while holstering. Deviate from Kydex and found many doors are closed. I like more traditional western style leather holsters the most, they tend to drop lower, making reach easier for longer arms. Not great for most CC unless wearing longer cover. But, draw wise? Range wise? Lot easier for my use.
Oh, there's some holsters out there that can be molded to shape, but if remember right, mostly if not all belt height. Thinking leather wrapped Kydex?
* A sometimes simpler quicker holster fix for range use to drop holster is to just simply loosen gun belt a few sizes, let belt drop more to one side and use some sort of thong or lace tied to leg from and to holster to hold holster more in place. Gun belts usually are a few sizes larger than traditional belts, are usually meant to sag or droop. Above is using two belt system. Drooping one belt system can lead to burned buns among other things?