It's not they are hard, per se, I think maybe the right word is tedious. Each coral head has to be fed or it will die. They usually open up near lights out, tho', you can get them to open during the day. They need a shady overhang since they are not light lovers.
The main problem is, that, if you have a frag with 20 heads, and you feed each one, that means nitrates. These can bump up your nitrate level. Also, your inverts will learn about feeding time and try and pick open the coral heads.
Some people pull the frag out to feed it; some cut a plastic coke bottle up and put a 'ring' around it when feeding. I feed mine alternating mixtures of mysis, enriched brine and cylcopeeze. I tried squid, which worked fine, but, high protein and my nitrates bumped up
You could put the frag under either ledge.
SH