Or they might be doing it just to keep their fingers 'warm'. I recall during AlphaStar, there were a lot of questions about why the human pro APMs were so high

Or they might be doing it just to keep their fingers 'warm'. I recall during AlphaStar, there were a lot of questions about why the human pro APMs were so high when it seemed like a lot of them were null ops, and apparently the answer is that they do that just to keep their fingers going and reduce reflex reaction time. (As you can imagine, this would be very bad for imitation learning...)