Producing subtypes don't understand at all PoLR. It's like an aspect of reality that they are missing in their brains. So they need something to cover that absence; usually it is done with creative and the opposite sign IM of the same type that is in their HA (for example, in the case of LIE-Ni, they don't have +Si at all, but they cover it with +Ni creative and -Si that is in their HA).