Fwiw, nerite snails appear to think diatoms are candy. They eat them in preference to many other things. So that's good.
MT snails are actually very good algae eaters too, and if given something with algae on it, will swarm it to get as much as they can. But they are small, so they may take longer at first before you notice they're working. They don't lay eggs. They have live babies, a few at a time, which they release at the water surface at night.
They do breed fast, but you hardly see them most of the time simply because they do like to burrow. They help keep substrate from forming any gas pockets, and they don't eat plants. They are hard working clean up crew and if numbers grow too high, they're not hard to sell, or you can simply destroy the extras. Do not release spares.. if you have too many and don't want to or cannot sell them, kill them quickly and throw them away.
I have them in every tank, and would not be without them. I sell the extras two or three times a year and never have much trouble finding a buyer.