From my experience, game design is quite often about projected possible subjectivities and purely practical stuff. It's all about streamlining the experience so let's not worry if remarks get detailed. All might be taken into consideration, but bear in mind that there is a certain essence of every game that should rather be preserved with all the possible changes around it. What's more, proper design should bring a perfect exposure to this very area of the game.
The dynamics of "Imagined seconds" are really interesting. All participants focus for some time just at one player who performs a contained part. That feature is unique, refreshing and also game-wise weird as there is practically no interaction at the core.
It might seem counter-intuitive then to suggest:
1. Moving away from one table filled in by Timekeeper. When everyone has own chart, Downtime should be much lower even with many players, as tables are filled simultaneously. Right now it's considerable, especially when you headline your game as "for any number of players"… ;)
I'm pretty sure this will still not hinder the Interaction. Here it mostly takes the form of comparing the bets, which is indeed done during the betting, but can also be expected after the round and is then not forced but naturally encouraged.
2. Informed choice would be another issue I think of right away. Should the "bets" be as seemingly random as they are now? A natural mechanic would be to provide incentives for the player to describe the sound in sufficient detail (such a mechanic is exemplified in Dixit, when you lose points when no-one guesses, although it's also not good for you if everyone knows the correct answer).
What else?