I don't think site based ASIC is disingenuous at all. What...

I don't think site based ASIC is disingenuous at all. What you're describing sounds like net profit, and I agree with Galena; FCF is a better figure because it cuts through the accounting.

The reason site ASIC is more useful is that it enables comparability between "projects". Sure, they're a single mine company now but that that's not to say it'll stay that way. Resource companies evaluate opportunities (i.e, a new mine, a new well) by calculating their capital and operating cost against a given required rate of return (discount rate). That return is supposed to include head office and interest costs; the latter of which feeds into their weighted cost of capital. But just think through the practicality of it - could you imagine an Origin or a BHP trying to pro-rate their HQ costs when contemplating a new mine? And what might that do to other mines? It would be a total mess.

By-products, gold credits, etc aren't a consideration here.

Nice summary Galena!