Youareright in that lagering at lower temperature can produce "better" results. Iwata just trying to answer the question on whether or not you can lager at elevated temperatures. Remember that lagering was invented before refrigeration , so Mother Nature used to determine lagering temp.
We are kinda talking semantics here. "Lagering" at 50F would produce almost NO results distinguishable from typical conditioning. I get that this type of conditioning is a continuous spectrum, but 50F just is not within the defined spectrum of lagering. Lagering is a defined type of conditioning at near freezing temps. I don't want your earlier post to make someone think they can get "lagered" results at 50F. You can't, no matter how long you wait, anymore than you can lager at 100F.
Lager yeast are even still plenty active at 50F, and you definitely at least want your yeast to be dormant and fall out of suspension to clear a lager-style beer!
You are right, Mother Nature, i.e., science, STILL determines lagering temps - it is the same today as it was XX hundred years ago. The fact that they used to lager in iceboxes and caves instead of refrigerators is pretty irrelevant, it just has to be cold enough to produce frosty condensate on the finer proteins in the beer to make them more dense and fall out of suspension. The colder it gets, while staying above freezing, the finer and finer particles you are affecting, and the cleaner and cleaner the beer gets.
You can't lager at 50F, no matter how long you do it. 50F will not pull the finer protein particles out of suspension. It's not cold enough. At 50F, you are just plain "conditioning."
I think it's grey as to what temp you would consider "lagering" to start at, but by definition it's as near to freezing without freezing as possible, and I don't know many that would consider 50F near freezing. That's probably short sleeve weather in San Fran this time of year.
In my experience, you don't really start to get the clean crispness associated with the lagering process until about 38F at the top end, but if you intend to lager, you should definitely do it right, which is closer to 30F.
OH, BTW.....GO 49rs