I agree on the plating monti.... find a place where it can grow where it will not shade other corals. In the past, I have had 3 or 4 different birds nest all grow together and get intertwined. I did not see any issues other than after a couple of years the mass of birds nests were a bit unsightly. The inner parts would die off and the mass would grow outward to get light. It was pretty cool until I started trimming it back. That is where the dead under all the growth showed. I ended up pulling the whole mass out and cutting it up into frags. I remember having ORA green fused with some bird of paradise... an then some ponape and a yellow all in about a quarter sized chunk. Unfortunately I lost the frag.
So, to answer your question... yes birds nests can be in close proximity. They do grow fast...and will intertwine.