Hello,
Yep, it’s not explicit in the documentation. However, here is an explanation on how to customize your instance.
Looking at the application_config_internal.js file, you can see that there is a way to configure that there.
// Teams are always loaded during the initial loading screen (for the first tab only if
// SharedWorkers are available). Allowing users to be members of multiple teams can
// make them have a very slow loading time. To avoid impacting the user experience
// significantly, we're limiting the number of teams per user to 3 by default.
// You can change this value here.
//AppConfig.maxTeamsSlots = 5;
Your instance admin can then follow the steps in the documentation, namely copying the www/common/application_config_internal.js to customize/application_config.js if it’s not already done and edit the AppConfig.maxTeamsSlots variable to fit your needs (: