The views from our top floor flat via the Velux windows in the loft extension are indeed exceptional they come into their own on ceremonial fly pasts I've lots of photos of the Red Arrows & Battle of Brittan Memorial Flight etc.

Another bonus is my TV picture with the same Sony TV has improved exponentially as I have added ferrite's the resolution I would liken it to going from VHS to Blu-ray.
As for the health issues most of London is the same, I would really be worried if there were pylons carrying  high voltage National Grid Cables nearby, or repeating a weeks  camping with my then young daughter on a friends farm in Cumbria subsequently  to discover it was down wind of the Chernobyl disaster contamination  for some years his sheep had to be gathered twice a year for testing & had to be brought off the fells a month before sale eating  grass from tested uncontaminated fields.  

addendum:  I am adding that the WIFI is also cleaner PC screen no longer has interference

 

Before leaving the subject of electrical isolation, can you have too much?

I think in my case, the answer is around 5 stages before the limiting effects are clear. My environment is relatively quiet compared with some members here, my music room is a separate annex, the incoming mains is dedicated and the noise is fairly low with a reasonable sinusoidal waveform shape, and I'm far away from the closest SMPS and motors in the main house.

My 5 stages of isolation are:
1. 4G mobile (cellular) data
2. DXE ethernet filters
3. Uptone EtherREGEN with moat
4. Optical link with JD094B-C SFPs and ipolex cable
5. Gustard U18 with moat

After this level of isolation, self-generated noise will begin to take precedence.

Let's talk about vibration control. I can only relate to what I've learned, which is a tiny window into the subject.

There are two main types of support: coupling and decoupling. The first couples energy transfer between components, presumably to something else that can absorb it. The latter isolates and damps each component. I have learned that coupling doesn't work for me and have systematically eliminated all hard spikes from my system. They have the effect of hardening the sound and exaggerating the edges, the exact opposite of what I want to achieve.

Some decoupling solutions, like sorbothane, don't provide much in the way of damping or control. However, it has its uses. I have a box full of different types of decoupling supports and footers and have fallen on two that absolutely work for me and are used exclusively throughout my system.

The two products are RDC Cones and Black Ravioli Pads and Big Pads.  RDCs are used for the Solid Tech system rack and the Electric Beach S1NX shelves.  Black Ravioli are used under each component, including the grounding boxes.  The thing about Black Ravioli is its ability to not just isolate, but provide an extraordinary amount of damping from a seemingly inert hard block of constrained layer material.  The whole idea is to prevent damaging vibrations from reaching into the electronic components and particularly sensitive sections such as the clocks.  All components are microphonic to a degree and vibrations rob the music of fine detail and soundstage.

The only exception to the above are the Townshend Podiums supporting my speakers.  They do a similar job but on a macro level to support the 160kg speakers by 'floating' them on dampened springs.  Instead of preventing vibrations from getting in, they prevent the speakers from vibrating and coupling it to the floor.  In so doing, they greatly enhance the quality of the sound throughout the range and tighten and deepen the bass without loading up the room.

The final part of my solution is to add weights on top of components, which seem to enhance the Black Ravioli, providing further mass damping.  I use granite placemats & coasters, and Schramm door stoppers, but there are plenty of elegant solutions available for this purpose.

I thought I'd try the BNC plug shielding touted in Head-Fi and somewhere here (I couldn't find the post) as I have lots of spare sticky-back copper foil. I've put some around all four BNC connectors of my two clock cables. This is acknowledging that sinewave clocks are more sensitive to shielding and noise.

I hear a little more depth and a little more tiny detail in the soundstage. I'm not complaining for a zero cost tweak.

Now that I know it works, I'll apply a new lot more tidily and ensure full coverage.

That's the same technique l've used internally on your Multiflex 141 BNC John.

It's electrically connected as I fold the first section underneath for the copper to make contact with the BNC body. I don't want to create an antenna.

I shall return to these and decide on whether they're staying once I solve my DAC to power amp phono run.

I do virtually all of that, except wrapping the router in EMI shielding - but it's far from the main system.

I use twin DXE filters at either end of the Supra Cat8 ethernet cable.

It also has a heavy weight on top and has its own QA grounding box.

I know that feeling. Listen to it, don't fiddle until something changes.