The concept that the power & everything else is limited by law, makes the idea of boosting the audio a great idea. It's how several of the legal FM broadcasters have "accidentally" found audiences where they should have no coverage.
So maybe this 446 radio will have better coverage that other legal 446 radios, if they have truly boosted the audio level.
But I am not sure about the claimed micro size. My daughters had 446 radios of a similar size a before they got amateur radio licences & they were of a similar size & I have used (or tried to use) 446 radios belonging to others of a similar size..So are they really that small compared to the competition??
My other issue is £100 for a pair of 446 radios
I could buy a box full of cheap dual banders for that.