Actually the racket I made the test on had older grommets but I doubt it would matter.
EDIT: I also did some tests once on a Prince O Port racket with nice smoth painted surfaces. The greater the bend the more the tension loss.
Everyone has the right to be stupid... it's just that some people abuse the privilege...
Balance - 31.0 cm, Weight - 358 g, SW - 346 Kgcm^2