To me, it seems like AlphaStar is actually at a disadvantage in its ability to micro, and has to make up for this in its macro level strategy.
When you have geniuses like TLO and MaNa, average APM is more on the level of 300-400 consistent and 500+ in engagements. You're definitely correct that APM is not 100% effectively utilized. I would say maybe around ~40% of actions could generally be considered spam clicks. That still puts AlphaStar at a definite disadvantage in its ability to enact micro level strategy.
- The APM constraint by AlphaStar seems to be average APM (or some variation thereof), while it reached 900+ APM in battles -- again with 100% effectiveness. That's insane and definitely beyond human capacity.
- It didn't waste APM in the early game (when humans are warming up and spamming APM), further leaving slack for when engagements came.
I mean, when gauging practical applications, we shouldn't be too concerned about good reflexes and superhuman effectiveness; however, part of the point here was to gauge other aspects of cognition more related to strategy, large decision spaces, etc; and in this setting it makes sense to constrain those non-strategic (more mechanical/tactical aspects). I'm sure e.g. constraining humans to <300 APM for example would change player style/effectiveness that much, while e.g. the blink stalker micro displayed in Game 4 vs Mana was really reliant on massive parallel single unit/group control (blinking every single low health stalker individually, engaging from multiple sides simultaneously, etc).