G&M wrote:

Where is this junction box placed. In theory you are simply copying the
arrangement normally in the CU but in a CU one usually tightens up all the
screws when you are in there wheras this junction box will probably never
get touched again. Screws unfortunately do come loose.

Well, that's true - but it's also true of screws in sockets and light
fittings, which might get tightened once every 20 years or so!

The junction boxes will be going under the floorboards, so accessible
but not very easily. I believe that use of junction boxes in this
situation is compliant with the regs (screw terminals are ok as long as
they are accessible).

--
Grunff