Here's an interesting bug for you: trying to make Metalleat seeds in Thaumcraft 5 is currently impossible because adding anything that isn't an active ore for making native clusters to a crucible with Metallum and Ordo in it will result in a Silver Native Cluster. My best guess as to why is that there either IS no silver ore, or it's disabled in the configs somewhere. JEI shows the recipe as 1 Ordo, 1 Metallum, and the spot in the recipe where it shows what you are supposed to throw in is blank.