Joined: Jun 2007
Location: Metro Detroit
Most UDPs are not correctly tuned for Crankshaft torsions IMO. And I built and tested the original 4.6L dampers years ago, they are not one size fits all. Crank dampers have a hard life, especially when you start adding more power.
If the rubber is poor quality or not the proper durometer, there is going to be issues. Removing mass from the ring and still using the same type of rubber will work the rubber harder.
I could go on with what if's for hours. But I know I wouldn't play with any pulley that is not OEM or no proof of testing with torsional data.
A properly tuned damper should go 100,000+ miles without issues.