Sending Jackson down does nothing, there is nothing left to prove down there. He is taking good ABs, he is working counts, he looks fine in the field etc. I have used the Cowser comp, not to say he should be sent down, in the sense that Cowser looked particularly lost at times during his callup last year. Jackson is facing some professional adversity for the first time as a professional keep running him out there.
The fortunate thing is he isn't hurting the team in a significant way right now, and when it finally does click the Orioles will be just that much better.