Hello Dashboards Team,
We recently received the request to modify the hover text in our ArcGIS Dashboard. Unfortunately at this time there is no additional functionality to do this, it's just a toggle on/off.

We propose there be a configuration option to modify this hover text (similar to map pop up configurations) and for it to support Arcade (dynamic calculations).
Please consider this enhancement as we believe it will improve the functionality within Dashboards.
Best,
Amanda Huber