There is a simple workaround for this which might work for some, depending on complexity!
Delete all default content for the smart module, and reduce top/bottom spacing of the module to zero. At send out, the module will not tak up any space in the email. If you for example have 5 variables, create 5 smart modules, 1st one contains default content, the rest only contain the rule dependant content and spacing is added for the content, not the column.
Aside from that, pretty impressive hubspot haven’t added an “exclude if rule not met” option 