Testing question

[Regs]

The initial verification would be to the equipment you have installed.....ie the CU and associated gear,such as the RCD's......not the existing outgoing circuits.
IMO essential tests on existing unaltered final circuits would not include R1+R2. IR tests and Zs would be essential because of the changed characteristics of the new protective devices.
R1+R2 tests would be advised but not essential and could be noted as a limitation on the EIC if not carried out.

Can anyone please tell me:

You say changed characteristics i get the Zs part as you could be going from bs3036 rewireable to 60898's so different Zs's. Where does the IR come in please?

If you don't do R1+R2 then how would you confirm polarity?