I like the concept overall.
So it is pretty much a hub drive like system implemented as a mid drive.
I guess you will have one chain for the rider on the right side and another belt/chain on the left that goes directly from the motor to the hub.
Does the motor have multiple internal gears ? Otherwise this will be too much like a geared hub system.
No multiple gears on the electric motor, a single gear ratio. This is the beauty of a dual drivetrain.
Well sized electric motors with the proper fixed ratio don't need gears, they can deliver all their torque from zero to max on a single gear ratio, usually around 1:9 or 1:10
So the pedaling side is there to provide two things:
1- Additional power from the rider (using gears, because we are not as strong and efficient as an electric motor).
2- Input for the pedal assist.
Based on the pressure applied to the cranks and the pedaling speed, it can decide how much additional power to send through the separate drivetrain.
This also means that changing gears is way less necessary, because you can get the motor to deliver all the power you need regardless of the pedaling speed.
If you are in the middle of a hill in the fastest gear (smallest cog), when you apply pressure on the pedal, it will send power to the wheel through the separate drivetrain and get going just as well.
The slowest gears (large cogs) on the pedaling side become mostly necessary when using little motor assistance.