As someone intimately involved in making a LOT of noise (as evidenced by the accumulation of videos of the Howard Kennedy house band on YouTube) any step towards protecting the venues that are critical to the live music environment is good news but I am not sure this idea works, either legally or commercially.
An easement by its nature requires a dominant and servient tenement and these proposals seems to be site specific so the process would appear to limit the operation to an identified development and a named venue. There are no doubt examples where that would work, and I have recently worked on a lease that effectively contained exactly what is proposed here, but neither the easement idea nor the lease I negotiated has any operation outside the immediate properties concerned. Change of ownership can trigger a change of response and the launch of nuisance complaints and permitted development can trigger a change of use that will not sit well alongside an existing venue.
Faced with this proposal I could imagine property owners taking a pre-emptive strike either for their own benefit as owner occupiers or as a precursor to development. In either case a successful claim may be the death of a venue before planning permission is sought or becomes relevant and once the venue has gone neither the agent of change principle nor an easement such as is proposed would have any effect.
But if an easement can be created allowing a specified level of noise why can that not be acquired by prescription?
Alongside the legal argument there is also a commercial one. Trying to sell flats or houses marked with a deed saying that there is no right to complain about noise presents a negative image. Is it not better to say that adequate measures have been taken to protect against noise? That is the background to the agent of change principle. Our lease contained a covenant not to make claims of nuisance but it also included detailed provisions allowing sound attenuation works to be carried out as a positive approach to offering peaceful co-existence.