feather duster

Vermatid snails can grow and spread quickly, and other than possibly effecting water flow if you have a very dense population of these snails, they should pose no detrimental consequences to other livestock.
When these snails get bigger, they do send out a mucus net in efforts to trap detritus and other food stuff. This doesn't negatively effect neighboring corals, other than by possibly annoying the coral. In which case you can either move the coral or remove the vermatid snail!

 

You can also plug up the top of its hole with putty/epoxy, which may be quicker and easier!!!