I really don't understand why tennis is so clogged. Sometimes you have to play 2 matches in the same day in 2 different categories.
There will be a week of Games left after the Tennis finals, it could have been managed a lot better. This will surely lead to a lot of dissatisfaction from the players.
And rightfully so! This was too much if you ask me. 24 hours is a must or at least close to it and Olympia isn't just any tournament. Fans and the world in general wants to see the best play against each other in their best possible shape. Somewhere they said that the goal is to play 1 game per day, but as you said that shouldn't be necessary. But if they want to pull it off at all cost, then do some rescheduling based on the results of the games such that the fairest outcome is achieved in terms of time to rest for each player on average.
I mean there is no question that if Zverev loses this game, there will be drama right afterwards. Don't understand why those in charge would risk that in the first place. It is not only the player who will complain, but German fans across all social networks. As I said he complained and the response from the ITF was "sorry, schedule already been made". As if it was not possible to introduce slight changes, especially in a situation like this.
But it is solo sport. Look how merciless coaches in football are: if the breaks are too short, they simply send their B team to League Cup games, like Klopp once did. Nobody wants to see that, but it is the consequence. There is no B Zverev to be send to the game though...