Hey Stephen,
Thanks for reaching out.
Modifying the pro/map/content.php file is actually a great approach here, and the recommended one, but the best way to do that is to NOT modify the file that is inside the plugin.
Instead, create a new file in your theme at this location:
[your-theme]/tribe-events/pro/map/content.php
Make this version of the content.php file a duplicate of the original, then make your changes here in this theme version.
This way, you can update your plugins and the changes will not be lost. This should not cause problems and is a great approach.
To learn more, check out our “Themer’s Guide” here → https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Cheers!
George