Prop to High RPM on downwind

I've been taught to set the prop to high RPM on final, but I don't like this
very much because then, when I run my checklist for the first time on downwind,
I have to leave one item "open."

So what's wrong with doing it on downwind? (This in a Cherokee 6 or and Arrow)
It seems to work fine, does not disarrange the engine, etc. I suppose there
is some small noise increase, but hardly much.

So (1) is everyone taught to do it on final? (2) Why? (3) What's wrong with
doing it on downwind?

TIA