Could there be added a setting for this to only work in specific biomes (like oceans, beach, etc)? To prevent unlimited water but let this work in areas where it would make sense?

Last I checked this the biome borders weren't aligned enough for this to work in a way that wouldn't betray expectations, i.e. ocean water would sometimes blend into other biomes.

So unless there's ever an errorproof way of determining whether a block of water belongs to an ocean, I'd rather not implement something that only works half of the time.