Honestly , I don't know . I have had mated pairs of convicts [ not with snails as tank mates] and they definetly don't want anything around while spawning , as far as fry , by the time they hatched I'd aready removed what needed removing , if you know what I mean . For their size they are one tough fish .
How big is your tank ? If it's big enough you may be o.k. If the snail is big enough he may be able to get close enough to eat the fishes eggs .Like I said I can't say for sure . Maybe someone else can say for sure . good luck .