You could set the said sockets as a limitation with your client who is the landlord.
I assume the Landlord is requesting these PIR/EICR for insurance purposes, so by limiting the installation to it's bare bones, and then if anything happened the validity of the inspection may be brought into place with a rake load of limitations.
I would have thought though that the tenant must have sought the landlords permission to install all these services, in fact I would have thought that part of the tenancy arrangement would either have been the landlord installing them for his tenant, or coming to an arrangement with them to install themselves.
Either way I can't imagine them doing this off there own bat, if they have then there maybe all sorts of legal repercussions, and I would have thought then that the Landlord should order a full test, including these extra services.
There could be loads of ramifications on this, there could be arguments if there is a maintenance department on site testing is not needed. Think bottom line for me would be, give the client want he wants and make sure you have it in writing, so if he tells you not to test the services installed for/by the tenant then make sure it is in writing, and you document it also that is what you done.