After thinking it was a keg sanitization issue the first go-around, brewed another identical batch of cold IPA. Recipe is 100% Bohemian Pils, 13.5oz total hops with 6oz added 4-days into a vigorous and nearly complete fermentation with Saflager 34/70. Raised temps to 68F for 48hrs (87% attenuation). Cold crashed after that (removing the bagged dry hops) for several days before racking onto biofine in a keg for another ~5-days @ 34F. It's about a 2.5 week turn-around time which sounds roughly like what the commercial guys are doing. However, I'm getting hints of buttery-ness already I've gone nuclear on my kegerator lines (short of replacing them), but wondering if recipe, process, or sanitization is the most likely culprit here? (not much lager experience, but have made pretty clean 'quick' lagers in similar timeframes with 34/70)Hop creep could be an issue for you. Hops have enzymatic activity causing sugars to be slowly released and further fermentation. The solution is the same; you need a long enough diacetyl rest for the hop-induced fermentation to end and all the diacetyl to be eaten up, but it may be a few days longer than you are used to.
Have you ever experienced hop creep? I tried to make it happen 3 times to study it and I couldn't get it to happen. I tend to think it's not an issue for homebrewers.
I have tasted beers that I believe were effected by hop creep as I have judged a lot of IPAs in homebrew competitions. Most IPA problems relate to oxidation, but sometimes I get a beer that is hoppy and buttery. Unfortunately I am quite sensitive to diacetyl.
I don't think there is any reason to believe that hop creep is a matter of scale, i.e., hops act differently in a 5-gallon batch vs a 15 barrel batch.