Speed stability is the number one job of a TT. For years I thought that too. But it proved to be wrong in my system(s). It´s just another theory, it´s an illusion. How the music flows is essential, and the starting point is the turntable itself.
There is the actual speed you set your turntable at and speed stability - two different things
My first stereo when I was small 10? was a Hitachi am fm cassette player with microphone. I didn’t like the commercials on the radio so I made a cassette tape of favourite songs and played it for two weeks. Only that tape. Then one day I turned to the radio again. The songs I had recorded did not sound as good as my tape. They sounded slower and lethargic. Boring. It wasn’t until I was a little older that I realized that the cassette tape motor was running a little fast. But its speed was stable. I learned the difference between the two at a young age.
If your turntable has variable, adjustable, speed control....some like to set the tempo of their records to suit their moods. Can your Digital system do that ? The important part is that the speed you set it at stays there. It is stable.
Put four musicians in a room and ask them to play on four different consecutive days. They will play a different tempo on each day. Fill them with cappuccino’s before the fourth day playing and see what happens. Humans are not robots.