Marzia...
We have a production app @ promevogpanel that is a paid app, experiencing this limit as well.
If there is a reset or a limit you could lift, that would help us greatly.
When you speak of "managing the number of indexes that can be created in a short amount of time",
do you really mean, "managing the number of writes to the index bigtables",
or "managing the number of new indexes added to the app".
If you meant the former, rather than the latter,
would you suggest distributing the number of writes to indexed entities more evenly?