Turntable speed accuracy

Lewm ~ I have the TTWeights rim drive and the Timeline shows it does not have speed stability, this on 2 different TTWeights rim drive models. Does it sound OK? Yes but when I now listen to a DD table I can clearly hear the difference.
(dealer disclaimer)

Dear Skos, You are preaching to the converted. I am a confirmed DD junkie. I still do like my highly modified Lenco, however. I was unable to test it with the Timeline, because the spindle hole in the Timeline is too small to admit the spindle of a Lenco (or of my Kenwood L07D). This to me is a major oversight in the design of the Timeline, as I think it would have been easy to supply alternative spindle hole pieces for it, especially at the price. (I could imagine a removable rim-threaded bottom puck; three such pucks could accommodate all typical spindle diameters, with a snug fit.)

I think I remember your earlier posts on the TT Weights. It appears that their drive wheel and the rim of the platter have been re-engineered in their latest models or their revised older models. Perhaps those issues were resolved.

Lewn ~ a customer of mine has the TTWeights upgraded player with the new extended rim and still the Timeline showed it was unstable. Can he hear it? No but it didn't make him fell all warm and fuzzy.

God never meant for audiophiles to have a warm and fuzzy moment. If an audiophile is not worried at any given moment, he is compelled to search for something to worry about. Enter, the Timeline.

I notice very few, if anyone, is using a test tone and measuring frequency, as a means of setting TT speed. My limited experience is that the KAB disc is pretty insensitive, I have an AC motor and so the KAB disc shows perfect speed, however the 3150 test tone measured with the Feickert App, shows fluctuations of up to 5 Hz from a mean of 3150, after I have adjusted the power supply. The test tone takes stylus drag into account. So what are the issues with this method?