That's an interesting point about a more 'wooden' result. I believe that has a name where being consciously aware of what you're doing lowers ability, or in this case creativity or subjective evaluation. I believe that dip/plateau can again be surpassed as if you'd learned consciously first then internalized to gain proficiency. Alternatively, you could 'get in the zone' by turning off analytical overthinking somehow.
My impression is that real mastery requires periods of flow and periods of deliberate thought. When performing you want to flow, but practice should also incorporate the conscious and deliberate. Having the meta-cognition to reflect on where you are, where you want to be, and having the ability to plan how to get there are very important. I think this holds true beyond music.