So for right now, you cannot export all visuals from a dashboard into a single CSV/Excel file. I tried to see if there was a workaround with scheduling an export, but for that it seems that it is limited to pivot table or table visuals. And even then, they are still exported as individual documents. For a potential solution, I would refer to this resource (StartDashboardSnapshotJob - Amazon Quick Sight). This will allow multiple visuals into a single CSV/Excel, but it is limited to pivot tables and table visuals.
I will keep the ‘feature-request’ tag attached to this post to increase visibility to the support team.
Just wanted to follow up on our conversation. Did my response help in anywhere? Feel free to like the message if it did or respond with any further questions you may have about this topic.