Fleeting

Put it on the ceiling?

As already stated the description of the wiring is nonsense it is almost certainly PBJ.

Had this countless times you note it as a Limitation and in doing so it excludes it from the Report.

What size protective is protecting this cable?

"I have a decent idea of what I'm doing", no you don't. I don't need to do any calculations my experience tells me the 6.0mm² submain is...

Put it in the box you put in.

That looks terrible. I would have jointed in the box and bought some 6181Y through.

Metre = 100cm. Meter = A device for measurement.

I have some, have sent you a message

We like internals.

Circuit might be 40m+ long how can you be certain 2.5mm² is fine?

No picture then?

If you've had the cover off you may as well show a picture.

Thanks for the advice all duly noted 👍🙏

This needs correct design to ascertain the cable size and if you are in England or Wales notifying to Building Control.