Mine is wobbling quite badly, so took some time and did some analyzing yesterday.
So took the entire slipper assembly apart. Mounted the slipper shaft into a cordless drill and spun it very low rpm - the slipper shaft was true. So the problem is somewhere else.
Found that there was some free play between the slipper shaft and the slipper plate, where the parts meet at the hex. One end of the spring coil was interacting in the cavity of the slipper plate, This was forcing the plate to one side - some dremel work on the spring fixed that.
Where the slipper shaft and slipper plate meet, there is a sweet spot to get it to spin true. So you need to rotate the slipper plate and test, rotate and test.
Mine spins so much better now, did not manage to get 100% at least now its about 95% true
