The person who asked about it was also told to just check the MSDS, which sounds like a perfect idea to determine whether other toner contains iron. Since it's so common to have iron in toner it doesn't seem like it would be a problem for toner-transfer/direct printing. If we could get someone who has modded a printer for direct PCB printing (And it works well) to see if their toner is magnetic that would be really helpful. I'm guessing you'd need a NdFeB magnetic to see the effect, as weaker magnets are unlikely to show as much attraction since the iron (As iron oxide or ferrite) isn't likely to be over around 40-50%. I tried looking up any MSDS sheets for Pantum toner and haven't found a single one. HP, Brother, Canon... They all have easy links to MSDS for their toner, here's one for Canon that specifically details it containing 40-50% ferrite, and I found several others (Canon) that contained that or iron oxide at the same concentration:
-Larry