As per agreement via email on Jun 11, 2020:
Noticed that the discount is being applied to the grand total – however I would like to see if we can get the discount to come off the T&M only. So currently it adds T&M rate, daily fees and any additional insurance / products up, then reduces by 10%. I would like it to just reduce from the T&M element only as this is how our rental system is set up.
we can set it as a setting in the plugin. All the programming work to develop this will cost $225.