In the old days ATC may well have challenged a pilot with reference to continuing an approach below 1000ft when RVR was below “Aerodrome Operating Minima” - a defined minima for that airport, regardless of aircraft type/equippage/crew training. Indeed there used to be specific phraseology employed if this occurred.
However, AOM is not “policed” in this way by ATC any more (UK).
As a word of caution, I believe, the CAA have the power to request RVR logs and flight data.