I could testify keeping them well feed is a challenge if you have a tankful of aggressive eaters. My bluespotted jawfish has been with me over a year now and it eats pretty much everything I put in the tank. I feed my tank exclusively with home made frozen. (mysis, mussel, clam, scallop, shrimp, brine shrimp frozen mix with selcon and other vitamins) And my jawfish will eat anything you offer.
However, their problem is that they feel insecure leaving their burrow and if the food doesn't flow close enough to their burrow, they won't try to catch it. I have tried adjusting the flow of the tank and have even ran a tube right next to its burrow to target feed him. It only works for a short period of time before all other fish figured out it's a feeding ground near the burrow and all camp out there.
This indeed had cause my BSJ moved its burrow once because all the aggressive eater is hanging out by it's front door! I have tried target feeding and that results in the same situation. If I didn't have a sps tank, I could probably overfeed everyone, but it does not work well when you try to keep a low nutrient environment.
I think to successfully keep the jawfish happy, choosing it's tankmates are quite important. Somewhat like keeping mandarin dragnets / firefish / basslets. Just watch out from those wrasses, they are pretty but they could be BOLD! Good luck.
Steven