Unfounded.
And since they switched from hardcopy to e-file the wait can be less than three weeks when it used to be 18+ months.
But, if you don't want to be on record "linear compensators" are nowhere close to the same thing, but they "move" the noise all downrange. So for whatever you're shooting at it's loud as fuck, for everything behind the gun it's really quiet. But nothing close to silencer quiet.
When I shoot my 10mm pistol (supersonic) at an indoor range, the echo coming back is louder than when it fires. But I'm sure you can find someone who's actually measured the change in decibels from using them.
But if you put one with subsonic rounds, it's probably going to be quiet enough for what you want
Or just do the stamp