Mistborn using Fabrial?

[TheSurvivor00]

So if a Mistborn were to get onto Roshar, would they be able to use a Fabrial to make some items on Roshar into Allomantic metals, then burn those metal, like for example they turn a lot of food or something into a lot of Pewter? Would they be able to use it, seeing that people who aren’t Knights Radiant can use Fabrials like that, or would there be a problem with the metal, where it was unburnable?

[Quantus]

There is nothing particularly special about allomantic metals, so if they knew the correct alloys and could figure out how to use a Soulcaster (or bonded a spren) yes they could Soulcast nearly anything into metal.  There's a catch with the Fabrial Soulcasters in that it might be pretty rare to find a Fabrial Soulcaster that can do any metal, given that the Azir are famous for having one capable of Bronze, specifically.