I've got a situation where I need to add a socket for a warming drawer half way up a tall unit.

 

My original ring final wiring into the neighbouring "normal height" cabinet is only long enough to go into a single low socket, so I'd have to spur from this. However... The cabinet plumbing now doesn't allow me to get a socket in there at all, so my question is: 

 

Would you add a Wago/Wago box underneath the plinth to keep the ring intact and spur from this up to the warming drawer?

 

I assume this is more legit then having a daft socket underneath the cabinets.

Personally, yes I would go Wago box below the cabinet (assuming that's where the ring wiring is accessible). Although technically you could get back to it, it will be out of sight and a pain in the backside so a maintenance free junction makes a lot more sense than a socket.