If punishment has the problem of punishing being noticed as well as bad behavior, reward also reinforces being noticed rather than good behavior.

That's nowhere near isomorphic IMO. Activities usually viewed as laudable are hardly ever conducted in a cladenstine way, and if the judging authorities are rational and strive for objectivity, I suppose they'll usually notice those activities on their own, without signaling from the subject.

If you really do care about your child's well-being and development and simply keep your eyes open, you'll easily find out if they prove to be diligent, honest or compassionate - but to discover undesirable behavior you'll have to actively outsmart them.