Anyone go the BBB to hand - reg regarding mix and match

[Octopus]

So next week I have to add a circuit to this board:

My plan is to add a Wylex breaker ........... but how would the BBB wording cover this?

I haven't bough the BBB yet!

After all, its not me that added the 3rd party breakers

 

[Toneyz]

And I'd always install a suitable RCD for the same scenario, or walk away. I doubt you'll find any electric shower M.I.s that don't state this as a requirement.

What about other circuits in the bathroom?hence the checking for supplementary bonding.