Obviously the sleeve will allow the cylinder to be overbored, if necessary.
This is of little value if there are no oversized pistons. Our kx 125, with a sleeve, turned in to a nightmare. Few, if any, pistons available in an oversized configuration.
Before you sleeve, just ask what oversized pistons are available. Look them up in a catalogue and make your decision. We would have been miles aheead by goign to a 134 with a replate. Now we need a new cylinder to do so.