Major - are you saying that the wort must be chilled to pitch temperature to adequately absorb oxygen into the liquid through inline injection, for however transitory that may be? If so, could lagers be racked at ale temps and oxygenated inline to the fermenter, then allowed to cool down to fermentation temps without concern about oxygen remaining sufficient? Just wondering about the dynamics here - does the oxygen stay in the wort as it cools to its ultimate fermentation temp or is it "driven out" by the cooling process or absorbed by the yeast scavenging or both?
I have been using a wine de-gassing stirrer for batches that are re-pitches and liquid pitches - it gets pretty frothy and the yeast seem to make fast work of absorption/uptake. My last lager was re-pitched into 64F wort (as cool as I could get it by immersion chilling in 90F+ ambient temps last Saturday). It was racing within 4 hours and fermented at 58F for five days and completed well attenuated (1.040 to 1.005)...I can't imagine that it "needed" O2 by inline injection, but I have a stone that I haven't used in a few years, because the wine whip seems adequate (all my beers are pretty low OG, though). I may just revisit O2 injection.