This is low priority, but in the cases where people enter bad metadata in the Wax CSVs, it would be useful to have some kind of failure rather inscrutably borked up designs. I've been trying a few in the rubberstamp test site, but as I remove them from there if you don't mind I'll just document a few here.

The idea is not that Wax should actually handle these cases, but that it should break in a slightly less inscrutable way; ideally, probably, through either refusing to build at all or perhaps even through refusing to build a single item.

I can bundle these into simple collection or something at some point.