All amplified music in pubs should be subject to noise limitation.

Nothing is being proposed to change this. But your chosen method also adversly affects non amplified music.

Even where additional entertainment is in place, any resulting noise is still subject to the envirionmental legislation. So what use does this expensive red tape serve, except to provide employment to those who enforce it?

The problem with dealing with any noise concern with additional licensing permission is that it attempts to deal with it in advance. That is before there is any determination of whether there is a real noise concern being presented or not.

And in cases where it is determined in advance that amplified music should be prevented or limited, this also applies to non amplified music.

Surely it is better to apply measures to reduce noise concerns when and where they are being presented than to risk losing any music which is not causing a noise concern, which is the case with additional licensing permission?