"You
often cannot install a 4th technology ..."
Says who!
Please provide ... just one ... example, preferably an internet link of some credibility.
The cost of installation will be paid by the installer, if approved via agreement or the PUC if challenged.
The NHEC is not in the internet business. Most electric companies have decided not to jump into the fray ... wisely, in my humble opinion. They would/will use the existing wires, including the wiring in your house/busioness. Just plug into the AC connector on the wall!
https://broadbandnow.com/Powerline
Many years ago, I believe the last problem was getting around the transformer.
Maybe you should try bringing up mobile or fixed wireless or some other technology that has already been incorporated, in some areas, with no problem about "growing poles".
Why should NHEC spend COOP member money on something it will not use? Should they spend money on pavingf the roads the poles are on?
PLEASEEEEEEEEEEEEEEEEE!