Well it just so happens that I have a large open brain sitting close to my frogspawn. My camera sucks and im new to aquarium and coral photography so sorry for the bad pics. Anyways its the lowest flow part of my 75 gallon tank and thats where these corals seem to enjoy it the most. Im sure its not ideal having them this close togeather but its seems to be working in my tank so far. The brain doesn't seem to mind the frogspawn as they have been in that position for about 7 months. The zoas seem to be growing fine even though there could be some chemical interaction between the zoas and the shrooms or other things. Would the zoas grow faster moved to another part of the tank, maybe, I don't know. Would another variety of zoas fade away or die from being within this close proximity, maybe, I dont know. Maybe someone with more experience or knowledge could chime in.
Top right has red shrooms expanding closer to my red zoas, fuzzy green mushroom between red zoas and green zoas in the middle and frogspawn dangerously close to green zoas.
Brain sitting below frogspawn, tentacles get very close but i've never seen them touch. Also has elegance sitting beside the brain.