I think once you factor in the hassle/expense of changing tires, you quickly get away from the idea of swapping used tires back and forth for differing missions. Just not worth the hassle. I suppose if there were some 10K tires out there and you some 1K gumball track tires, you might consider it, but the actual variation in the tire mileages with the various tires available for a bike like the S1000RR aren't THAT dramatic, notwithstanding pure track tires of course. Even if there were some rock-hard 20K commuter tires available, I'm not sure I'd want them on my 180 RWHP bike anyway. Final consideration is that if you start keeping multiple sets around, then you are generally not going to be running as fresh a tire and tires calendar age.
My vote is to use them up, then buy some new ones. Repeat as necessary.