Just to provide more background, though not sure you would listen based on past experience, I have analyzed the problem in some detail. If you mount back the wheel for X-9, with the chain off by one cog than the position of the derailleur, usually the smallest cog, you are likely to destroy the cage. However careful you are, by inattention that one in 10-20 times you mount back the wheel, you will end up destroying the cage with the thin alu it is made of. Yes, you still can sell this type of junk to a multitude of customers who barely ever take their wheel off (even know how to do it) or even much use their bike.