After 43 years working in the defense industry I have a pretty good idea of what they’re doing to limit its functionality. The article is correct about the 20mm rounds (over 3/4 of an inch in diameter) and their travel distance being a concern. Even if they used target rounds, the round could travel almost 3 miles. Since they shoot between 4,000 and 6,000 rounds per minute, they’d send 1000 1/4 pound rounds flying in 15 seconds.
Given the effective range of 3,000 yards and the ceiling of our fighters being 10,000 feet lower than the balloon, it would be a crap shoot at best.
The military has equipment to limit transmission to/from the balloon. I assume they’ve been doing that since it came into US airspace.
You can see the relative size of a 20mm round here
https://en.wikipedia.org/wiki/20_mm_caliber#/media/File:50BMG_size_comparison.JPGEdited by thedad at 09:25:38 on 02/04/23