IMHO --
I would think a reef is just like a garden, at some point you've got to prune. I don't see how you can just let corals grow indefinately, unless either you are going to keep going to larger and larger tanks, or keep a very small number of corals so there is a lot of space between them.
Although I'm very new to the hobby, my plan is to go, within reason, for a very dense look, and prune the corals to keep everything in check.