> almost all G4 PowerMacs were sold with factory dual G4 CPU cards in them

No. As I said, almost all G4 PowerMac generations *include* factory dual-CPU models. This doesn't mean that almost all G4 PowerMacs were sold with factory dual-CPU cards. In fact, the majority (61% going by the number of models, not by the number of sales) of the MorphOS-supported G4 PowerMacs is made up of models with factory single-CPU cards.