I tune my new strings a half-step sharp, noodle on them for a while, re-tune a half step sharp, noodle, tune to pitch, go.
The whole process takes about a twenty minutes. The strings set well and I haven't noticed any reduction in string life.
Ditto ..i dont go hog wild on it..half step sharp.play a couple of the more aggressive song i play as i normal would then drop it back down a step..i have personally always done this not to "stretch strings" but to have the strings settle around the tuner which is where most of the initial loss of tuning comes from..its not the strain on the strings, those bad boys (epsecially agressive rounds) have to manipulate around their own ridges and settle into the coil where theyre gonna sit til you take em off.
the part that bothers me is that you said when you brought it up to your guy he got kind of matter of fact about the whole thing...its your gear and your money in his pocket and you have every right to ask any questions behind his work especially if you found something off putting.