[brandall10]

Their claim is the boom won't actually reach ground level for overland flights due to how they're profiled.

Of course that's the theory. The Trump Admin just allowed for a fairly audible boom.

[foobarqux]

Where is this claim?

[brandall10]

From the top of their corporate website, there is a video explaining this:

https://boomsupersonic.com/boomless-cruise

And from the top of their wikipedia page:

"is expected to reach supersonic speeds without causing a sonic boom at ground level by taking advantage of a physics phenomenon known as mach cutoff"

https://en.wikipedia.org/wiki/Boom_Overture