So you advise to wire from the DP switch in 2.5mm cable even though
the whole circuit is backed up by a 32A MCB?
Don't play with something you know nothing about.

I see no reason why this is not acceptable, assuming no insulation. Indeed,
it is the standard method, as I understand it.

The 2.5mm cable is rated to 27A (IIRC). The nature of the load prevents a
greater load than 22.5A being drawn. Diversity allows both parts to share a
32A circuit. The earth loop impedence and voltage drop on a short run like
this is very unlikely to forbid it, unless the run of 6mm is long.

It is no different in principle from running an unfused spur in 2.5mm on a
32A ring circuit, where the spur cable is also only rated for 27A (20A under
certain installation conditions).

Christian,