Or, is your question on becoming immortal contingent on the whole “under stress” aspect; meaning I could control my aging, even letting myself become old, then reverting again, to any age I choose, and then letting myself age natually again ‘til I chose to revert yet again, so long as I could control my stress? (much more interesting scenario!) because then we have to learn to have absolute control over our emotions, at every age, and if we reverted too young, then perhaps it would be too difficult to control our emotions and we would keep reverting until we were a zygote!
but the short answer is: Yes! Absolutely I would give it a shot! Just have to finally get serious about that Zen meditation or trying to become a Jedi! And I suppose I would never revert to younger than say, 25. (but it would be so damn tempting to be a kid again!!!)