Massive thanks for all the suggestions, I’m glad I’m not the only one and yes it’s hella annoying especially when sat down for the reasons DezB stated :D.
I have some spare fettling time tomorrow night so I will:
* Remove rotor, clean it with brake cleaner, reattach to torque and make sure no movement. (I have a spare Rotor I could try too actually).
* Make sure the right way around
* Check rotor for warping
* Replace mount (as luck would have it I have another)
* Replace pads
* Re-centre calipers as per hope video, and ensure EXACTLY centre!
* Check rear hub bearings ( I think they are solid though)
I’ve done this before to silence the prevuious squeeks but did nothing with the vibration issue.
If no luck I’ll consider securing the cable to the frame, or rubber washer mounts.
Thanks again, I’ll report back!