I heard this before and had always done it but wondered if I was wrong always with the last click as 0 or 1
Doesn't matter. When you get that deep into the limits of a damper's range, one click isn't gonna make a difference. In fact, the last 2-3 clicks might be completely useless as far as making adjustments. If your tuning has brought you to that range, it's time to revalve.
I had the rear damper gone over by the manufacturer and it came with a note saying run both adjustments inward and count clicks going outward.