So there are ways to prevent corals stinging each other, generally you just give each one enough space and when they eventually grow closer to each other you would frag them.
As for encrusting corals like Acros, Montis and chalices, it is generally advised to glue them to a rubble and the rubble itself to your rockwork. This allows you to remove the coral before it is able to encrust over your rocks and than you'll be able to either restart the colony, snip it back or to glue to a bigger rock.
This technique is also advised for other corals as well, as keeping an easy option to remove corals from their place would allow you to move them to a different location to meet their flow/lighting conditions or to treat them against pests/STN/RTN etc.
It is also highly recommended to keep GSP, zoas, palys, shrooms and others constrained to their own rocks as these would colonize (and terrorize) your whole tank if not kept in check.
