I am an IRI and my application was accepted on the actual instrument time not my IFR time. The CAA never even questioned it.
I raised the question about flight time logging at my last examiner renewal and the CAA view is that actual flight time by sole reference to instruments should be logged. Where for example someone is a multi crew pilot where all work is under IFR they will accept IFR flight time on the assumption that there should be enough actual instrument time within it. Hence the reason for the 4-1 exchange rate.