Thanks for letting us ask, appreciated.
From memory, I was first stating that some old designs/cheap copies of JHeads are fragile or not working for a long time (I believe because overheating leading to the formation of a plug in the cold end of the thermal barrier, but not sure on that).
My question were about :
1) what kind of design changes or testing did you go through to get sure your version is not subject to those problems ?
2) what kind of insurance do you offer to your buyers, can they send it back and get refunded if they discover it does not work as well as they expect (IE as good as a pristine current version JHead does) ?
Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.