Hello Craig -
Have you found a solution - I believe this KB addresses the need you are seeking for data driven alerts. - https://kb.tableau.com/articles/howto/how-to-reate-conditional-data-driven-alerts
Copying from an another Forum link...
Running multiple different alerts on the same dashboard could be done via a single calc that tested for multiple different conditions, or from three separate alerts set up on different dashboard panes, if the emails needed to be customized to the particular alert type being thrown.
Also, Jonathan Drummey found a trick that lets you hide even the trigger pane off to the size of the dashboard, if the way the emails look matters a lot to you:
Hope those are helpful. VizAlerts could be used if you really wanted something extremely custom, and didn't mind setting up additional software against Tableau Server.
Please mark the answer if helpful