There are different height factory pistons. At least one for the old style spring, at least one for the new. There has been some oddball pistons as well. Mix and match and you can get play. I've never seen one that was that sloppy with the correct parts. As for the spacer rings. If you melt the plastic spacer the clutch has been burned up anyway. The metal style cracks at the weld once in a while. Set the clutch clearance correctly (.025-.030") . Then the only way the spring can flip is if the clutch burned up. This clutch is applied initially only when being shifted into 1st gear at rest. The accumulator can soften that hit. The only issue I've ever had with mine is the teeth wearing on the clutch carrier which in my case is aluminum. A little machining and a spacer easily repaired that issue for good. In fact we use stock steels and clutches in that clutch. Unless there is a underlying issue, they go forever.
Doug