Add Line Chart as chart type to Custom Report

We make line charts with 2 dimensions (Month and Year) and single measure all the time.  Example below.

I see the the Custom Report only has option for a combo chart, which gets a line chart.  But not a line chart that allows me to add 2 dimensions and 1 measure. You can do this functionality with the bar chart, but I would like this in a Line Chart instead.

In discussions with Humberto Hernandez and Micheal Nordstromthis feature can be added by the end of the year, which drove our decision to purchase 300 licenses for our on prem deployment