Although Origin Live recommend placing their DC motor on the top plinth with a single screw, and although the OL DC motor is quiet, still there are inevitably vibrations that may be carried from the motor to the cartridge through the tonearm.
So I took the decision to experiment a bit and placed the motor on the bottom plinth, as the original Xerxes (AC) motor used to be. With the only difference that I did not allow the motor to rotate around its axis.
Initially, my impression was that the sound had become somewhat 'smaller' in comparison to when the motor was placed on the top plinth. Then, a few tracks and a few minutes later, I realized that the sound was somewhat cleaner and more precise and that gave the above-mentioned impression. It was perhaps the lack of motor vibrations and hence added energy around each note that made things smaller; but also more precise.
So, I will continue my experiment by having the motor on the bottom plinth, but I think that this is how it is eventually going to stay.
I do not know whether any other fellow forum member has had a similar experience with the two alternative motor placements.