I have a written reply from CAA that advises GPS can be substituted for ADF as long as the test profile does not require ADF so you definitely do not require an ADF if your aircraft does not have one, but you will need to find a pilot interpreted non precision approach that does not include NDB ( eg pure GPS) You will however require a proper DME for test and VHF radio with 8.33 channel spacing.
Less hope the examiners know this !!!