I can honestly say that now that you mention storing liner locks open makes a little sense. The liner is like a spring, and when open, the "spring" can be in the relaxed position.

This is sort of like saying that magazines should be stored empty.

Honestly, I am not enough of an expert on metalurgy to know if springs loose their springiness if compressed for too long. You know the saying: "Opinions are like ..." etc. etc. I have yet to hear from somebody with a PhD in the appropriate subject matter.