The idea of crimps are flawed and leakage around the two crimp bumps are likely. In order to pull a crimp tight, you need to bunch up material at the crimper's closure point. This means there is a noncontact area around the two raised bumps. Joint failures show this clearly, there are no embossed ridges at the bump areas and water stains show leakage at the point where the crimps are raised away from the pipe at the crimp bumps
Secondly why is pipe compound not recommended?
Screwed-tight pipe clamps stretch out, why do we believe cinch clamps will not stretch?
Viega "PEX Crimp Hand Tool", Viega-41723-User-Guide.pdf
Says:
"The maximum out-of-roundness of a
completed crimp shall not exceed .006".
This is the difference between the minimum
outside diameter of a properly crimped ring and
the maximum outside diameter of the same properly crimped ring."
"shall not exceed .006" is crazy, they are just looking for a way to blame the installer. This is plastic and thin stainless that is stretched by a hand tool inside a wall."