There were 2 conflicts, one with vanilla glass panes and the other with ice. None of these have changed anything. Would it be safe to continue playing on this world?1) There might be ID conflicts, check if a MFR config is in your config folder. If not, you can copy the config from Ultimate, it should be compatible.
2) I don't seem to remember MFR having steel, but that's probably just my memory acting up. If it has steel, they're interchangeable.