The issue of pictures or drawings showing laser exhaust port and intake and connection was discussed in this post:
IIRC, no blessed answers were given.
The Glowforge store isn’t open yet, so it’s not easy finding out what Proofgrade sizes they might carry. Strangely, it is hard to find out the size(s) of Proofgrade using search. The best I could come up with was (at which point I gave up the search):
I do not know how much room is required to store the free samples. I don’t have that issue yet.
(On a different topic, if someone could explain to me how to quote just a line from a post I would be appreciative. Thanks!)