You can resolve that issue with crimps very easily. I needed to install a much larger CU than the original and there was no space for it. Plus it was in an awkward place.
However I could fit a box of smaller size, so basically extended the cables from the old position to the new using crimps inside the box. THe main challenge is to make sure that the wires remain identified OK. You can buy numbered cable markers for this.
.andy
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