I don't get paid more when I work 9 or 10 hours, do I?

I am theoretically paid on deliverables, not hours.

Maybe so, but the deliverables expected of a full time worker tend to correspond roughly to some estimate of a typical worker's productivity. Or people are hired to perform particular kinds of duties, and expected to be reasonably productive in those duties given the time and resources allocated to them.

Your employment contract lists deliverables rather than work time?