Hello, if you submitted an idea to add drill through functionality to total lines can you add the link here? I would like to vote up your submission. I am having a hard time locating it on the Power BI community site.
My workaround to this is as follows:
I've got my table with a category column, a values column, and a total row. I can (as you know if you're reading this) drill though from each of the category's values, but not from the Total.
I copy that table, remove the categories and turn it into a simple Treemap, i.e. a single block of colour based on the Total. Users can then drillthrough from that to the appropriate page where the detail behind the Total will be.
Hope that's helpful to someone.