How to disable Ctools modal form from running on mobile devices?
You can hack wonders with a little "@mediaquery" and "!important". 
I used this little bit with "modal_forms", not sure if the #id is the same.

@media (max-width: 580px) { 
    #modalContent {
      position: fixed !important;
      top: 12% !important;
      bottom: 12% !important;
      right: 4% !important;
      left: 4% !important;
    }
    div.ctools-modal-content {
      width: 100% !important;
      margin: 0 auto;
    }
    div.ctools-modal-content .modal-content {
      width: 100% !important;
    }
}