It's a matter of definition. Probably you're right about the definition of hypomania, what you're describing is more accurate but quite some (by experience) professionals think otherwise. I know this state just too good, it's how I usually feel when not depressed & not on a NMDA antagonist - but due to the need of diagnosis, I began to define this as AD(H)D-like behavior. It wasn't just once, but repeatedly that professionals wanted to or actually put me onto dopamine antagonists when I began to feel good, which is quite rare for me naturally. Needless to say, antagonizing dopamine is no good when you don't need it, and it makes me even more restless but also anhedonic (and at some occasions even truly freaking out).
There are many graduations but being in satisfaction, positive-minded, calm, yet euphoric is just the ideal state and probably few people can experience that more than coincidentally. I myself am mostly either stimulated or lethargic, and quite happy when the energy state fits with the rest of my mind, e.g. stimulated and energetic or lethargic and fatigued. Mixed states are annoying and exhausting. One can learn (to some extent) how to use the energy, I'm not really there yet but at least I will do something productive like reading up about things that interest me, or write here etc ... this leads to some kind of reward too.
For me, the real border is where the ability to stay in control ends. This is hard to explain.. imagine drinking alcohol. As long as you stay within your limits, everything is okay, you get some effects - depending on you, from slight disinhibition to real drunkenness - but if you drink too much, something breaks off and you loose control. Consciousness sets in again some hours later, and you can't believe what you've done (or thought, if you remember it)-sometimes it's just a big black-out and nothing serious happened. The same thing with a different quality applies to psychotic breaks and to true mania, at least for me. There is no chance to stay in control, as if your brain takes you over for a while, if this makes any sense. Sounds crazy, I know, but can't explain it better.
Happened rarely luckily, and would have scared me at a younger age, but that's how it is.
hypomania needs care, but once one gets to know it and leans how to stay in control, it's a nice state. Specially the disinhibition but also general motivation is really estimable and enjoyable if you ask me.. that's what people drink alcohol for, just without all the negatives.