Algae turf scrubbers are the best natural method to control algae. They create an environment with ideal conditions for the algae which then consume almost all of the resources in the tank so algae only grows on the ATS. They act as a sort of nitrate/phosphate sponge. Most snails are opportunistic consumers that eat anything that comes their way. Since mine has been in operation I have not lost any snails. I have mostly Nassarious but also some Ceriths. I also have an urchin that is fine too although I occasionally spot feed it with a small piece of nori.
Since I put mine in around 6 months ago it has consumed all of my nitrates and phosphates and I no longer get algae growth anywhere in the tank, including the ATS! Initially algae grew like crazy on it but has dwindled to the point where it is barely green.
As a side-effect, after the hair "green" algae was gone, I got a cyano outbreak (purple/red). This I combated by upping water changes and reducing the light schedule. I have it down to just a light purple haze on the substrate which is rapidly disappearing.