Ideally, you'd have only one smoke on a zone. Unfortunately, I didn't install todays disaster where there are 9 smokes on 2 zones. Are zone expanders really that expensive?
Anyway... I'm now wondering about how to do resistors correctly when you have more than one smoke (either daisy chained or home run) on a zone. Do you have a resistor in each smoke, or just one at the end. Being a normally open contact (DSC 5010), it would make sense to have them in each smoke, but I've seen them installed both ways.