Yes, I checked online and they too test with a chimney at 15 feet.Pretty sure all stoves are tested on a 15’ chimney so I’m sure manufacturers probably fine tune them for optimum performance at that height. That 15’ height in a lab could equate to something else in the real world so I would also agree that it seems the VC stoves could benefit from a bit taller chimney than a typical non cat. Should find and read the EPA report test for VC stoves may be a few pointers in there.
Using the theory that more draft is needed to properly run the Dauntless through the cat doesn’t explain why I had the same high variability with the stove when I ran it without the cat as well. I’m just angry at myself for not doing more research on the stove and relying too much on company reputation.