I can definitely notice crust flavor differences, but trying to figure out the source has been very difficult. And there has also been the dilemma of detecting a difference but not really feeling that one was better than the other.
Temperature and time are obvious variables, but the strain of the various microbes in the starter are also important. There is no question in my mind that different strains within each culture are active in different temperature ranges. And the amount of time between feeding can effect the population of different critters. Some of these microbes are more sensitive to pH levels. The pH of the dough at the beginning of fermentation is different from that at the end. If you are doing multi-stage fermentations, starting low and then going higher can produce a totally different flavor than starting higher and going low.
At this point, I am too busy with other projects do the testing to figure out what is going on in my dough. Tartine bread has also cut into my pizza making, so I'm only making pies ~1 per week, tweaking here and there and slowly moving forward.