I'd rather not discourage consistent use, either. One valid purpose for modifying the rate could be soft botting prevention. Instead of handing people CAPTCHAs, just string them out on 40 seconds, 50 seconds, etc., as suspicion dictates.

What'd be great - and what I think would prevent some botting - is an official queue function. When I was filling in teal for half an hour at a time, I would have preferred to click a few spots in a row and let my browser do them for me. Automating an entire image would be ruinous. That's just a bot war waiting to happen. But if I could leave a dozen pixels floating, at any given time, I wouldn't give a damn when the timer says they'll get placed.