as i now see it - with the la platine on its own feet, the movement of the la platine platter (wobbles) was exciting the suspension via contact between platter and spindle. this in turn was leading to a noisy motor as it was receiving forces of up and down rather than just lateral. noisy motor then feeds back into platter chatter. and on we go in an unholy mess.
now, on rigid feet, the motor only deals with a lateral load and is much quieter. the double looped silk is the "lubrication" in the system. a little give perhaps. the silk thread knot is tiny relative to linen. plus less "large" as the double loop somewhat minimises the significance of the knot. i continue to get extraordinary W/F results with rigid feet on la platine.
having said that, a platform which could prevent motor chatter (such as it is) from reaching platine platform and hence tonearm would certainly help. rigid feet don't do as good as a job as the platine feet in this role ime.
i must admit i don't know if such a platform would best have the motor and platine on it or just the platine? it seems to me that if the motor is on it, then the same issue exists (motor chatter shared with platine platform and hence tonearm). so should be separate which would help since as @ledoux1238 points out, otherwise you are dealing with a very large platform.
if kept separate, then the only chatter the platine gets is from thread/speakers. silk thread is dampening i believe. speaker chatter unavoidable i think.