when you read the wheel building threads a common discussion/argument is what to put on the spokes when you build your wheels. I built my LB 35mm 650b wheels myself and not being a pro it was a learning experience. Some guys recommend spoke prep, loctite, grease, boiled linseed oil, anti seize or nothing. Recommended spoke tension is more of a range than a given. I built mine with DT Swiss revolutions which are so thin in the middle that windup is a bit of a concern and I used aluminum nipples front and brass rear. I opted to grease my spoke ends since if I needed to retension later on it would be easier with the revolutions and aluminum nipples. Then I tensioned to about 90-100 kgf on the drive side and front disc side, which is probably not enough. This equated to around 17/18 on my Park meter. I found that after a couple rides I had to retension a quarter turn and I may have to do that again. So maybe the combo of grease and lower tension is an issue but I just keep an eye on them. With a thicker spoke, brass mipples and spoke prep then maybe the wheel will stay tensioned forever.
In a perfect world and in the hands of very experienced builder you may get wheels that never need a true. I don't mind throwing them up on the stand and giving them a quick true. Routinely I will quickly pluck the spokes and listen to the pitch, like plucking a guitar string. A spoke that has lost some tension will have a lower note. Spokes on the drive side will of course have a higher pitch. A local bike builder says he always builds his wheels to spoke pitch. There is even an app for your phone that will tell you the tension by the pitch.
https://itunes.apple.com/us/app/spoke-tension-gauge/id518870820?mt=8 I don't have that good an ear so I will stick to my tension meter.
I replaced some spokes and a hub for a friend of mine. The wheel had been built by a local lbs. Before I took it apart I measured the tension. 29 on my Park meter. 1/3 of the nipples and been rounded and distorted trying to get it that tight. I think that was maybe over the top.