Good question. I hunted around at Elsie Pea Forum and couldn't find any mention of one.
There was a note that that some of the original 370-xxxx models had a flat slide stop and the later ones were rounded which was easier to work with. That said, even the rounded one isn't terribly easy to use, especially with gloves.
I think it is a good idea, if executed properly. Whenever you want to lock the slide back, it is fairly difficult with the small tab that they provide. It may not be possible and still hold with the overall small size and also maintain proper holster fit, but I would pay for a good enhancement.