I like that idea of having one special item that needs everything else! :-) I will check that out. Cool way to compare your base to others, like "how many rubber duckies do you produce per minute?" ^^

Thanks! That's what I was thinking! I'm not sure if you're on Reddit, but there's been this ridiculous trend going around of people showing off assemblers that can feed hundreds of items.
I'd also like to exclude any item that requires a rubber ducky, or is downchain of rubber duckies, so someone could use rubber duckies in a formula. Right now that would create a loop.

You inspired me to upload the mod https://mods.factorio.com/mod/Complex_Rocket_Recipe which is not THAT extreme as your mod but at least puts all the science packs into the rocket part recipe.

Lol. Your mod is made extra complex by the fact that I can't understand a single word.