I am curious, if you were overflexing the boot so much as to deform some of it, why were you put in the boot to begin with?
The boot fitter said that boots stiffen up in the cold. It's normally true. He also said that the ability to flex in the shop wasn't indicative of the flex while skiing. Also true.
I think I am also guilty of wanting to believe that the Salomons would stiffen enough in the cold because the fit was so perfect. I was a Salomon loyalist and believed their 110 rating to be what I needed. It was their stiffest boot, yada, yada. I accept the blame, too.
To answer your second question, I didn't ski the boots before the heating process, so I can't say whether it had any effect at all. I was unaware of any flex differences in the shop.