in my mod i have an invisible hidden entity as part of a building with allow-automated-item-insertion&-extraction both off, but the filter helper still suggests what the hidden recipe makes as something that can be filtered, this mod could probably check:
https://lua-api.factorio.com/latest/classes/LuaEntityPrototype.html#has_flag
https://lua-api.factorio.com/latest/concepts.html#EntityPrototypeFlag