Has Uponor tubing undergone extensive testing?

YES!  Uponor has undergone 35 years of rigorous testing.  Under the supervision of an independent laboratory, Uponor PEX was subjected to 3 decades of testing at temperatures of over 239F, and at pressures 239 pounds per square inch (PSI).  When the 30-year life cycle was completed recently, not a single piece of Uponor PEX had experienced any breakdown or failure.