That is an interesting idea, although it goes against the KISS principle.
The Thetford valve is a little special, but I'm sure one could retrofit an electric valve to the bottom of the toilet. Or, perhaps it would be easier to install a small motor in front of the existing valve, but still under the toilet, to operate the valve. Mount a disc of some sort to the motor with a bar screwed to the edge of it, and the motor now produces in-n-out movement for the valve. You've got power right there already to run the motor, so that is not an issue, and no thru-hull holes.
Dave