Collection factory or collection proxy? Which one to use in this case?

I tried the “dynamic prototype” thing, but you still need to add your collections somewhere statically for the builder to find them, I didnt understand how you use it really, if you need to add all the collection “somewhere”…
Maybe you can add them as a ressource directory?
This was my first attempt, but I couldnt make it work, so I’ve decided to go the static path with many collection factories