The thing about the assumption I had not taken into account, thank you for rooting that out. I did get the feeling that the terrorist-type actions to Zahel linked closely to what had become a terrorist-type group, at least on Roshar. Either way, it proves that there is at least one Full Feruchemist alive, and could create the unsealed metalminds.
I would like to state my liberal use of the word terrorist here, I understand it can be a sensitive word, but I think it somewhat applies to the ghostbloods, at least for the Rosharians.