Surely the installers understand that there is a big difference between watering an established lawn and watering a lawn to establish it. If they were to get mad at me, I would let the homeowner know which is the best watering times for the new sod. Set the timer and tell the homeowner that if the timer gets changed, the warranty will be voided on the sod install. Let the homeowner get on their rear.
My two sod wholesalers suggest watering the same way; 4 times a day at each zone set for ten minutes. This keeps the sod moist and promotes vigorous root growth. After a week, water twice a day. Three weeks, water schedule to return to normal. Follow these guidelines and you have a healthy lawn. Take into consideration though that I live in S.E. New Mexico(desert) and the day time temps are anywhere from 93-110*. Big difference between here and back East.
Sanity, is on the verge of DULL.