Lots of sympathy with this plight. Great to hear that someone has done the needful and rendered MoCA style modems over pairs of copper. I'm probably a customer for that.

I'm currently running MoCA over spliced coax as part of the local connection and not amused by the 5ms latency on it. Also running 100mbit over cat3 I found in a wall which does work, but cat3 in another wall can't hold 10mbit. That link actually can hold 70mbit of vdsl but after a nearby lightning strike slagged various hardware I've moved the vdsl modem back to the BT wires entry point and run the output through some fibre.

And there's a wifi bridge between two other points. And some ethernet running outside the building. Previously also ethernet-over-mains that I might bring back now that I've learned what spanning tree protocols are so the periodic reboots they inexplicably require can be tolerated transparently.

Also the connection to the internet itself is crap so bonding vdsl, starlink and 5g through the openmptcprouter project. Just lots of redundancy and self healing hacks all over the place to give an observably solid connection.

Which is a rambling way to say that if you're in Britain and your network connection brings you sorrow, it can be forced to be acceptable with application of more time and money than other countries require.