I'm J.Leslie, anyway. I have run probably close to 200 tests at different aperatures and exposures. In doing those I found that what you say is true, although I further found that the ambient temperature of the lite box itself has more effect than the exposure time itself. For expample if it take me a while to set up my shot and the lite box gets over 130. I set tests for
f5.6 4 secs, f8 8s, and f22 64s and they all look the essentially the same.
Then I let the deck cool to its pre-warmed 95-100 F degrees and do the same. This set also matches closely, BUT they look nothing like the first set.
Since I started trying to bring in color, my thoughts were similar to yours, but this test has me reconsidering the importance of the length of shot and more about how long it took me to set up. I also drilled 30 or more holes in my light deck to help it cool faster, since it seems easier to maintain the cooler temps than the warmer ones.