I prefer to not examine this issue in a frame of pathologies. In the individual case, concrete symptoms and behaviours of course depend on the unique personality of the affected individual. Yet, when you know a person good enough, it is not that hard to recognize the changes taking place under hypomania, and from what I can tell they seem to generalize well. It is exactly not the possible impairments that interest me, but what I subjectively experienced as an improvement to my default condition.
I should have added that I have tried several proposed methods of cognitive/mental enhancement, none of them fully delivering the particular mixture of symptoms that hypomania did (for me):
Nootropics, to the extent that I‘ve noticed an effect, came with unwanted side-effects.
Physical exercise obviously does the trick, but only goes so far raising and stabilizing mood and clearing up thinking.
Meditation also regulates emotions and increases self-reflection, but I could not notice any motivational gains.
Achieving flow states usually is very tricky as one has to adjust the difficulty of the task to one‘s competence all the time, something that is not achieved while taking care of routine business or hard problems.
Following your proposal, I would have to try something like perfectly dosing modafinil and nicotine while steadily keeping in a state of flow, which I had to consciously reactivate everytime after perfectly timed short workouts and meditation sessions. I doubt that even this would lead to the desired outcome. What may sound even less convincing to you, but actually is my point: mild hypomania felt „natural“. I‘m in danger here to glorify this episode, but cannot see how the first few weeks of it were unhealthy in any way—I was simply able to do more mental work in a day than I could normally do, while being happier than I usually was. If that is sustainable in any way is exactly one of the questions I would like to have answered by further research.
Instead of tweaking numerous variables for some individual with unpredictable outcome, why not examine the condition in the population, find out more about its mechanisms and make it accessible in a controlled fashion as a full package?
Thinking about the responses, I have to come to the conclusion that this is a rather bad idea. The positive symptoms which I remember very intensely just don‘t make up for the decline in critical reflection of what one is actually doing, thinking and feeling. I had suppressed that to some extent, but it is clearly a major part of what I went through. Thanks for pointing out this aspect. Personally, I will probably try to work on healthy habits, routines and stay on my medication (what I would have done anyway).