Would it work?
How did the demo sound compared to regular FM?There was an experimental demo in Las Vegas a few years ago at NAB that put something like 12 stereo streams on an all-digital FM.
But it's not an approved standard for broadcast yet, and no broadcasters seem to be rushing to get rid of their analog audience.
Same thing on AMAs has been pointed out here many times, the vast majority of consumers don't buy new radios anymore. Optimistic penetration of HD into the public has been sitting at 19-20% after 25 years since the introduction of HD. The distribution of HD radios has mainly been via vehicle sales. That means if a station were even allowed to go full digital, there wouldn't be enough listeners that would likely hear it anytime soon. It would be like opening an ice cream shop on an island where you are the only resident, hoping someone else came along and found you.
Consumers don't buy single-use products on the chance it might be a benefit in the future, considering that smartphone in their pocket do so many things right now.
But that's the thing, no modulation type or requirement to buy a new radio will ever attract listeners.Same thing on AM
I don't think MA3 on AM would bring in Listeners