maintenance depot recyclables should an optional output, similar to research labs
when setting up a new maintenance depot, you need to select the recipe, even though there is only really one recipe.
in the early game this is a completely pointless step
when you unlock recyclables, if you want recyclables from maintenance, you need to select both recipes in existing depots, and all depots you build afterwards
this can be solved by simply making the recyclables output "optional" in the same way as research labs