Got some stuff done...It looks like the stove holds 4 1/4 fluid ounces when really full. 4 ounces if you don't want it leaking inside the lid. I filled it up completely and set it upside down with the lid on. (I made another stove using the reverse side...much better seal) It will let some alcohol seep by at a pretty slow rate. When it's not full to the point of alcohol leaking out of the fiberglass insulation material (4 ounces) the lid should do it's job perfectly.
I did a "realistic" burn longevity test where I filled it with 4 1/4 ounces of alcohol and lit it, boiled 2 cups of water, hit the lap button, paused the timer, then blew it out. After that I cooled the pot, pot stand, windscreen, and stove by dipping them in cool water. I then repeated the process without refilling the stove. I did this until I could no longer boil the water. Here are the results:
First boil: 6min 51s
Second boil: 5min 52s
Third boil: 7min 21s
Fourth boil: 9min 02s
Total effective burn time: 29m 08s
For some reason the second boil was very fast, then it slowly tapered off. I assume these correlate to the amount of fuel left inside the stove.
I also made a windscreen today and tested it out...quite a bit haha.
Windscreen Tests <---- Click Me!