CU change and 17th edition regs

[DJM]

That was an interesting diversion, but can anybody answer my original question?
Assuming the cabling fulfils teh electrical tests, will the physical protection require changing due to 17th ed when transferring circuits from an old CU to free slots in a modern CU already in situ?

 

[BS3036]

To the 16th, all your wiring should have been in safe zones. To the 17th, all your wiring should be in safe zones. but in addition protected by RCDs (unless protected by blah blah...). And you intend to have the moved circuits RCD protected.

So it's hard to see what will need to be ripped out, unless you know that the wiring is not in safe zones, and it's hard to know how you could tell anyway.