^ Now that you mention it, yes, they wont' work with converted Lemmini tilesets, as Lemmini tilesets have no support for labelling pieces as steel. (SuperLemmini tilesets, on the other hand, do.) Of course, you could manually mark the pieces in the graphic set tool, but this would take a while - and indeed, it's probably quicker to use your existing areas. Just check that they do cover the steel terrain properly; it's possible they may not in some cases (being 1 pixel off due to rounding).