I would be cautious here - the persons involved with much of the prominent sewer/fibre corporations in the UK are extremely untrustworthy. Bournemouth's experience here a decade ago is instructive (https://www.zdnet.com/home-and-office/networking/bournemouth...).

I personally lead the effort to see a Fibre-to-the-home (FTTH) network deployed in my hometown of Quincy, Illinois. While this was eventually successfully implemented (with no thanks to any external firms, all done locally by our rural county telco coop) we had a false start (https://www.govtech.com/archive/quincy-running-fiber-through...) thanks to i3, the same chuckleheads who scammed Bournemouth through their Fibrecity effort. I likewise ended up with egg on my face, as the public figurehead for Quincy's fibre campaign (https://khqa.com/news/local/bringing-google-high-speed-inter...), but my only concern was the wasted time and money, and loss of public trust, for our community and its efforts.

I would simply recommend all involved be highly cautious; not because any of the underlying technology here is untrustworthy (although I'm skeptical of the technique for many reasons, most of which were well outlined by Jacquesm above) but rather because the underlying firms have their history rooted in nearly two decades of unfulfilled promises and wasted taxpayer funds.