IMO fine to move it back to KOP if that's comfortable. The hands-off test originated because riders with different top and bottom dimensions will need different saddle positions, not just KOP, to get their center of gravity in the right place on the bike so that they're comfortable and the bike's weight distribution is good.

KOP doesn't seem to have anything to do with knee health, power production, etc. More important measures are: do your upper arms make a 90° angle with your torso? Is your back straight? Are your glutes involved in your pedaling?

Your saddle height sounds fine. I think as long as you are comfortable on long distance rides and the bike handles properly when cornered hard, you're fine. If those things turn out not to be true, take another look.