I am also puzzled by the talk of dethatching on cool season vertical grasses.
I liken it to combing your hair with a strip of duct tape.
If you are managing you irrigation, fertilization and mowing frequency properly and keeping the soil open to air circulation, via aeration, you shouldn't be dealing with thatch issues on vertical turfs. Cultural practices ARE the key and if they don't fall into your service offerings, then it's your duty to educate so that a system doesn't develop that's counterproductive to the services that you are doing.
Verticutting or any soil disruptor is going to break your pre layer, which is why most will aerate then follow with preemergents after a cutting or two can be made to redistribute core soil.
Leave the random ripping to the bermudas, zoysias, etc. and just aerate and low cut/bag those Bend yards to get them started off, then apply your pre. Visited the year before last, stayed in Sunriver, very nice area with a fantastic park downtown on the river. Loved the pedal bar circling the park, hated the winding streets that change names without changing streets..lol