Hello Jeffrey. While it is true that acidic foods like tomatoes/juice may not do well with lightly seasoned cast iron, on the other hand when it is seasoned properly there are no ill effects whatsoever. When I say properly I mean over time. I have a few pieces that I use and I use tomato based products in them without any problem. And me, about them aluminum inserts, it would seem to me that you are defeating the purpose of using cast iron. You would be in effect cooking in the aluminum. And about the acidic foods eating through the aluminum. I seriously doubt that. If it would eat through that aluminum, I damn sure would not be wanting it in my stomach. :o ;D