And if there is something I couldn't handle on my own, I would refer the customer to one of my more experienced technician friends, possibly at the risk of losing said customer.
What does voicing of the hammers mean? What does that service entail?
I believe in and promote "full piano service". When people call us to ask about tuning, we translate this to mean "I want my piano to be more fun to play". Sometimes tuning is the main issue, many other times it is only part of the equation. With full service, we try to service the whole piano and this almost always includes some voicing of the hammers. Full service technicians usually charge more, but the value is greater. I am suspicious that your technician didn't have a good strategy for fixing your pianos problems. Even some high-end expensive brands can have excessive action noise.