Or does it have to do with resources being periodically deposited or something?
Income is per-second. Some expenditures are per-second. Some expenditures are per-frame.
But now resource auto-conversion is per-frame, so that breaks the old assumption that income is per-second. All the code that was actually tracking the resource flows and how to display them is from before my time, so it's a bit of a wrestling match
I'd have put more effort into getting it just right, but it appeared likely at that particular moment that crystal would become something else and autoconversion would no longer be necessary, and I could go back to the simpler model.
Now that's looking unlikely, so I'll have to figure something out.