Short times with the 1000 is just knocking off some of the "peaks" and leaving the "valleys"
Yeah, I realize that as I do that some with a 500 pad but not pressing "firmly" though and followed very lightly for 15 seconds with a 2000 or 4000 pad, but what was surprizing to me is that the pressing on a 360 pad firmly for 30 seconds leaves some pretty deep grooves in ball. However, I will try that the next time in place of a 500 grit pad and see how it goes.