Which of the following is a requirement for preserving dashboard customizations?

Preserving dashboard customizations primarily involves maintaining the actual configurations of those dashboards so that they can be restored or replicated as needed. Downloading dataflow or dashboard definitions is essential because it provides a backup of the current structure and content of the dashboard, allowing users to recover or apply these settings later.

When configurations change or there is a risk of losing custom settings due to updates or reconfigurations, having these definitions stored ensures that all alterations can be reinstated. This practice is fundamental in analytics and reporting environments where dashboards are key for data visualization and decision-making.

The other options, while related to the larger context of managing dashboards, do not directly contribute to the preservation of the actual customizations made within the dashboard. For instance, changing user permissions affects access but does not safeguard configurations. Documenting changes may be valuable for tracking modifications, but it doesn't serve to create a tangible backup of the dashboard itself. Reassuring users about the stability of the dashboard may help with communication but does not contribute to preserving its configurations technically.