As often as you like Josh, treat it as a meal and use it as a treat. ie going to a restaurant and having a meal as opposed to just having dinner at home.
Personally when I feed my hoard with any frozen food, it's a treat for them and they enjoy it more. I feed mine on frozen bloodworm, glassworm and black mosquito larvae. They love it. I too have a lot of small mouths to feed and the above suits all mouth sizes. I have tried brine shrimp, but they are not too keen,and also daphania. These tend to murk up the tank water for a little while as they are small, but hey each to their own.