I don't know, I like to use it for reassurance when certain deep bunkers show portions of the base terrain. If you excavate them deep enough, the terrain will always protrude and I still need to see the finished bunker to assess its viability. Also, the mesh preview is always helpful for making screen shots to show to the general public, as it makes sure of clean bunkers instead of showing, well, ungodly visual messes.
No idea if this might also come in handy on that fine day when we get POT BUNKERS!
Seems also a bit facile to get rid of something just because it's partially defective, rather than to try and make it work. Making a build and loading up the game to go check on bunkers? Surely there ought to be a less complicated way!
So I would recommend leaving it in. To avoid certain nasty side-effects, how about programming it in a way that the moment another icon is being activated (or CF is switching to the Unity terrain engine) it automatically toggles off?