Could you tell me what feedable familiars you have, and what items didn't show up? I guess it's simply a matter of configuring Feed_keep.txt, but maybe not.
One thing that the script is being perhaps too conservative about is hiding items that are in your inventory, but have an item to keep as their ingredients. For example, I put the cocktailcrafting garnishes in the default Feed_keep.txt, with a quantity of -1 to indicate that all garnishes should be kept (coconut shells for examples won't be considered when the script is looking for items to feed to your slimeling). If you also own a Hobo Spirit, Advanced Cocktails and Superhuman Cocktails will never show up either, because they have garnishes for ingredients, and nothing that can be made from them is considered.
I did the same thing for spices and noodles, if you have a GGG.
I decided to filter things like this because this is an ascension-oriented script, and I think anyone in HC/Ronin would like SHCs and reagent pasta to be filtered out.
I added a way to add stuff to keep, but I need a way to show the list of things to keep in order to make configuration easier. Or the script could check for HC/Ronin and only filter out items in that case. I don't see myself regenerating MP with those familiars in aftercore though.