On the vape volume, it's pretty easy to take a plastic bag of known internal maximum volume, inflate it, seal it around the outside of an e-cig such that the atty holes are inside the bag, and time the vaping required to empty the bag.
For a 510, with all holes open, I did this with a 750 mL bag, time was 60 seconds for 12.5 mL/sec or 60 mL for a 5 second vape. By taping one or more of the atty holes, the resistance can be increased, and the vape volume lowered correspondingly.
I'll probably do the test with an auto-battery 4801, which has a lot of resistance with only 2 holes (and I can tape one of them if needed to tweak the flow resistance). I've got the extended volume carts for the 4801 (0.5 mL) which hold the same volume as a 510 cart. I'd prefer to use an auto-battery 401 (quite superior to a 4801, IMO), but the 0.3 mL cart volume of the 401 is too limited for what I want. I could use multiple carts, but the integrity of the weighing is very important, and the less I futz with the e-cig between initial and final weighing, the better.
The trick now is to take the suggestions on surfaces and find a HDPE bottle that's strong enough to stand a vacuum to which I can attach a valve and have the seal be vacuum tight. Being able to see through the vacuum container does seem awfully attractive.