Well that is referring to the balance of the 1500 hours, so you've already had to have 750 hours in a registered aircraft and they're saying the rest of it can be in a registered aircraft as well. I suspect the "not more than" phrasing is just to align the phrasing with the other options as it doesn't make any difference or maybe it's closing some loophole that I can't see. In short, the entire 1500 hours may be in a bog standard registered aeroplane.