When the water that is mixed with any protector evaporates, only the active ingredient is left behind. One gallon of any protector will only be effective at covering so many square feet.
You can add all the water you want, but you are only adding water. When Scotchgard is diluted 9:1, it must still be applied to the same amount of carpet as if you had diluted 4:1 or even 2:1. That gallon of concentrated protector will only cover about 1,000 sq. ft of average residential carpet.
Diluting a protector with more water only makes the carpet wetter and means it will take longer to dry. If you are diluting at 9:1 and covering more square feet of carpet, you are not applying enough product.
Sorry to disappoint. But lower dilution such as 4:1 or even 2:1 with Maxim allows you to protect the carpet with less water but the same amount of protector.
I totally don't get this. Higher dilution rate means less protector "per sq ft" as you are applying. If I meter Maxim at 4:1 it would apply more protector than metering it 8:1 as I pass the spray over the carpet. There is no way to tell exactly how much protector chemical is on the carpet by time or technique, you put an even coating on the area and move on.