Specify border color on modules in the drag-and-drop editor

Right now, the only way to manipulate a border in the drag-and-drop editor is by setting the Template Format to “Boxed”. But this feature is limited in that it applies a border to the whole email, from top to bottom.
We need the ability to specify borders and rounded corners for each module contained within the email. There are other areas in HubSpot that let you specify borders and rounded corners, why not expose these options at the email module level? I need this functionality in order to implement email designs my creative team is mocking up.