I would seriously consider either allowing the tank to mature more and get a thriving pod population started, or add a fishless refugium. A newly cycled and stable aquarium just won't have the population available to handle the constant feeding of this species.
I would also do as recommended and demand that you see the fish eat first. My LFS
swore that my leaf fish ate mollies when I purchased it, and this could not have been further from the truth.
If it does eat, I would quickly attempt to vary its diet to something other than brine. It isn't very nutritious, chopped up mysis and zooplankton would be much better.
Decide on what is best for the fish in your own good judgement, if you don't get it now there will be others.