we did a lot of work on trucks to stop the skidding , its pretty endemic over many a year and many a vehicle
finger design and finger flatness have a lot to do with it you can see diaphragm fingers curved, flatend, , burnished , ground, didly squat and so on over
a range of clutches
there's less noise from an old worn and nicely loose thrust and the continued alignment as the thrust is operated is essential.
most lever geometry is pretty hopeless , pitching the bearing even when on a sleeve .
concentric throwouts is the best answer, but thats a very expensive solution on a Triumph.