As I understand it. ... Using wago connectors or similar inside a generic electrical enclosure (such as a back box with a blank plate on it) is fine, provided they will remain accessible for inspection.
Indeed so. ... or, as has been said, simply leave the socket (which will be hidden behind a cabinet) there.
OTOH if you want to make the old position dissapear completely rather than having a blanking plate ...
Whilst everything you go on to write is true,it's not really relevant to the OP since,even with the backplate, it is effectively going to 'disappear completely', because it will be behind a kitchen cabinet. However, in relation to others who might actually want to completely 'lose' n accessory ..(whose previous location IS going to remain visible ....
1. Spring-loaded connectors in a generic box are not an approved method for inaccessible joints. Afaict to count as a "maintinance free junction box", the box and terminals must be approved as a combination.
That's true,although I don't really understand why the manufacturers do not describe, and mark, the connectors themselves as 'MF'. It's surely the connectors themselves that determines whether they feel (rightly or wrongly!) that the joint does not need to be accessible for inspection & testing, regardless of what enclosure it's in. However, they don't
. You could crimp or solder in a generic box, but that has it's own issues.
True. Maybe not even in a box if adequately insulated. It's just me, but, if it has to be done, I would personally be more comfortable with (
properly) soldered joints, in a box, than with either crimping or an 'MF' JB!
All the maintaince free junction boxes I've seen are designed for fitting in a building void, not for burying in plaster.
I can't remember whether the manufacturers say anything about this but, as I wrote ...
Theoretically, yes, but I personally would not want to literally 'bury' any sort of JB, 'maintenance'free' or not (e.g. buried in plaster)
3. If you obliterate all evidence of the accessory then you can't really argue that the associated safe zones are safe anymore.
It's a bit more fundamental than that. If the accessory that was the only thing creating the 'safe' zone is removed, there is no longer any 'safe' zone for people to argue about
However, in cases like the OP's there is no problem in 'obliterating all evidence of the accessory' if some other accessory (in his case, the new, moved, socket) still creates a relevant 'safe' zone
Generally as a result of this, if you want to get rid of an accessory and don't want to leave a blanking plate behind you should re-route the cabling from the floor or ceiling void.
Agreed - unless, as above, something which will still be visible creates a relevant 'safe' zone.