Thanks Peter! Not yet, I'm quit happy with the TechDas kevlar belt. Also the tension is set as mentioned in the manual. Less tension as possible, as many as necessary.
Florian, I once owned a Micro Seiki SX 8000II. It is a great table. I did a bunch of experiments with the connection between the motor and the platter. I went from the non stretch Micro belt to dental floss to a very thin thread. I then carried those experiments with another higher mass table the American Sound AS1000, and finally the AS2000, my current table.
I prefer thread that is fairly loose, and also long. Moving the motor away reduces motor noise migrating through the top shelf into the platter. A loose thread furthers this by reducing motor noise reaching the platter. My platter and bearing are different from those on your AF3, so I do not know what you will hear, but I think it is worth experimenting. For me, it was about bass quality and a more natural presentation.
I have only heard an AF3 once at a dealership so it was hard to know what the table was doing, but I suspect your new turntable is really excellent. Good choice.