Extruding or subdividing cube in editor

Im using cube objects as triggers in my game and then checking whether the player is facing toward and moving towards the cube. On a small scale this works fine but trying to scale it up is going to start making issues. Im wondering if there is an easy way I can either extrude out the faces of my triggers or to scale out my triggers and then subdivide them along its length so that I can then use the vertices as more accurate measurement points than the origin. I think I could use Mesh class but as far as I know that doesn't update in my editor, and I could manually build the whole thing every time but that would be extremely time consuming. Anyone have any thoughts?