That would depend what firmware the console you dump the transferable ctrnand from. If say you dump it from a 11.0 AND it overwrote A9LH, it would be game over. But from what I know it won't overwrite A9LH, because if it did people wouldn't be able to use a 9.2 ctrnand transfer after installing A9LH on 2.1 if they didn't have a backup.If it did overwrite it though, you'd be at 9.2 and could easily install it again