Talk to me about flywheels

[NewArt]

So while transferring over the ancillaries from my dead Boxster engine to my reborn Boxster engine, I noticed that while the clutch, pressure plate, and flywheel looked good, the flywheel spring-back test failed. The last times that I drove the car, I didn’t notice any problems or vibrations with the clutch. I’m thinking that I need to replace the flywheel because of the spring-back test, but I’m not sure why. Any knowledgeable opinions?