I too set my anchor by reversing at 1,500 rpm. Since I have a feathering prop, my thrust in reverse is about the same as my thrust forward and 1,500 rpm will power forward in 30 kts of wind or better.

But the point of setting is to bury the anchor. Then if the wind comes up to 50 kts later, the anchor will bury a bit further and hold.

So setting the anchor is about testing, not necessarily at extreme conditions. The only time I really dragged (and I never set it at 1,500 rpm) I discovered I had an old tee shirt wrapped around the fluke which prevented it from setting. If I had tried setting at 1,500 rpm I would have discovered this.

David