Since I really like the idea of the handgrip with trigger, I want to suggest developing a base plate for light weight support rods (diam. 15 mm/spacing 60 mm/distance to optical axis 85 mm) that not only allows attaching the DB16 to a tripod, but also has a mount for the grip, including a built-in electrical connection to the camera.

Alternatively, or in addition, base plate and grip attachment could also be in separate blocks, which would allow adapting the complete rig to changing centres of gravity. In this case, I presume that a cable connection between the grip block and either the camera or the base plate will be required.