The reason for three sets of steering bearings was inconclusive. Suspected that crap bearings were replaced by crap bearings etc. I just replaced mine this fall myself and used the "Best" bearings that Canadian Bearings sold which were SKF at ~ $32 ea. There's a big thread here on that also.
I meant that if a corner garage certified the bike they may not be as thorough. Done at a BMW Dealer they may spend a lot more time on it. That's all.