I have trouble figuring out the lift improvement reaching but your track change here is impressive. I'll check it out more often.

It's easier to determine the CB lift going to windward. But I don't see many degree changes on the compass, beating, so much as course change on the gps track.

The windward test is pretty easy in that you sail as close to the wind as you can, then drop the board and observe the increase to windward on the gps. Little changes except the decrease in sliding to leeward, which I find varies from hard to measure to impressive depending on conditions.

I've been told you may see it also in your wake, which will narrow as leeway decreases.

Then again, I can't count how many people have told me they don't put their centerboard down because it makes no difference.