I probably have more blue clove polyps in my tank than anyone around
Here's my take on them..
I've had them for YEARS and at first I was worried because of all the horror stories that I heard about them stinging and killing off corals. Over time I discovered that this actually isn't true. It may be true for another variety of blue cloves but the ones I happen to have do not seem to sting anything. My blue cloves butt up against corals of all sorts and even cover my clams but neither my clams or corals seem affected.
They do however spread VERY rapidly and can reach plague proportions quickly. If you do not want this then I would take preemptive measures to eradicate them. They are quite easy to smother with epoxy or scrape off with a tooth brush. I find them somewhat delicate this way. It may take a couple of toothbrushing sessions and you'll want to use a HARD toothbrush rather than a soft one or a used one that has gotten soft.
I actually like my blue cloves and let them be. So far I've noticed some of my LPS like calice are able to over run them without any problems. For most SPS it's a bit of a stalemate so to allow sps to encrust into blue clove territory I just clear a path with a toothbrush or epoxy.
You can see another example here of blue cloves touching one of my SPS frags but not causing any harm. No signs of stinging or warfare whatsoever.
In fact, this particular montipora was able to out compete the blue cloves in the far right corner, killed it off and has encrusted over that patch without my intervention.