You said you didn't think there was anything special about Uponor's material, I disagree. I think they are using a process to make the material different than any other HDPE and that process is difficult to get correct.What's to disagree with? I coulda said it better than I did, maybe. You said it better than I did. The stuff cracks when the temp's not right and these plastics have been around for decades
I think it is this difficulty that is causing all these issues.