This suggestion is mostly for making the ironworks relevant after getting the gold depot perk, but I also think it has some merit to be applied to the other production buildings secondary drops.
As we know, the current system has some production buildings randomly produce rarer secondary drops, such as the ironworks producing a small screws/springs randomly on some ticks. My suggestion would be to have the amount produced scale with the production of the building, where for example, an ironworks with 1k production will produce 1 small screw or spring at a time, but an ironworks with 3k could produce 3 at a time, while still having those "producing ticks" occur randomly.
Alternatively, you could make there be a range of values where the *maximum* scales with the buildings production, for example an ironworks at 5k could produce 1-5 screws/springs at a time, with each number being equally likely, and further keeping these resources fairly limited if that is of concern.
Overall while I understand wanting to keep these resources limited, I believe this suggestion, or even a modified implementation of it would be a great way to bring relevance back to upgrading some buildings such as the ironworks, as well as give people reasons to further invest their silver in other production buildings like steelworks in the case that someone might be motivated to chase for runestone mastery. I hope you consider this suggestion or at the very least have gotten inspiration for other ideas that might help achieve this goal :)
