I happened upon a package of Kodak sepia II warm toner. At the moment, I am away from my darkroom, and so do not have access to standard plastic trays, but I do have aluminum ones. However, I notice that it says rather ominously in bold: "do not use metal trays". So, pardon me if this is a silly question, but what would happen if I did use metal trays and ignored Kodak's advice? 

