I know you said Rotella looses its grade after 2 hours, but if you change it after every ride wouldnt it be better than running Amsoil for 10 hours? It seems to me like the oil would still be in grade and there would be less contaminents in the oil after 2 hours vs. 10 hours.
Ten hours was a one time test that I ran, and was only done as an experiment. The run time was what resulted from a 4 day trip to the desert over a New Year's holiday one time, and for me, it answered the question, "do I need to change my oil while I'm out here?" I already had run oil samples from shorter intervals, and based on those, I was fairly confident in the oil's ability to stretch that far. Ten hours, or 4 days, either way, is beyond my normal interval of 3 ride days. Ordinarily, that's something like 5~8 hours. Sometimes less. Since my desert race weekends are normally 2 day affairs, I'll change oil with only two days on the oil if I'm headed to one of those.
As for contamination, it depends on what you mean by that. Wear metals and other solid contaminants were at acceptable levels in the sample (iron was a little high, but not considering the presence of the transmission). Total Base Number was still excellent, so acidity from combustion contaminants and fuel residues was not an issue either. Some oils deal with that better than others. So in all, there was nothing really wrong with the oil at that point, and the next 4 day trip I take, I'm not going to worry about it.
Changing daily, you're using 3 times as much oil as I am. Something you may want to consider when each quart comes with a "Carbon Tax" attached.