Tom, when you vacuum seal the 18g bags, you you suck the bejesus out of them until they are a small hard lump?
I used to do this Dave but not any longer.
I just suck most of the air out a couple of days after roasting and leave them like that for a week(ish).
For longer frozen storage I use the little plastic take away containers that hold a perfect 18g.
As a corollary, when I sous vide meats I don’t “suck the guts” out of them as I believe that it works to remove moisture from the meat while cooking.
Tom, I think you should pose this question to Lyrebird.