Right, I'm with you on the cost benefit of starting earlier. If I knew I'd be hired by a Major I'd definitely move the date up. But my concern is that some have told me that if I submit my app now, without an ATP, it may just get filtered by some computer process because I don't have the minimum requirements or get tossed in the "look at next year" bin. Obviously that would delay me working there even longer and hurt more than waiting 3 months.
If it doesn't penalize me to publish now without my ATP then that changes my calculus.