As with knife sharpening (which I have done semi-professionally for several years) I use the weight of the blade or less.

You are dealing with very fine corrections/enhancements to a bevel. I liken the abrasive to the hammer size. You use a sledge for large adjustments with a powerful overhead swing. A 2 ounce peen hammer uses much shorter and less powerful strokes. If you are still using power at the fine adjustment stage, you are not where you think you are.