I've had the unit out of the door, and yes, an electric motor spins a worm gear which engages a geared pulley that pulls a cable cw or ccw--just like your drapes.
The problem with simply pulling out the motor and putting a crank mechanism in its place to turn the worm gear where it's located. This might actually be possible with a flexible cable such as is sometimes used with ratchets or screwdrivers to transmit torque "around corners".
The other option would be to to replace the cable with another that runs to a spool on the manual crank itself, but again it's a question of whether the geometry of the door and assembly have a place for such a thing.
If it's the switch, it has to be taken out and apart and rebuilt with 3D-printed parts, after which the motors might still have to be taken apart if they've seized from disuse.
My own fantasy for this is a wooden lever mounted near the floor, but I can't imagine the details of the internals.