I am not sure that "cleared ILS approach" is completely without ambiguity. It seems that in some places this means that speed control has been cancelled and in others it doesn't.
That is not to say I don't think it could find some application in the UK FIRs. Perhaps to aircraft in Distress or Urgency or when it is very quiet. On the other hand, since these conditions are quite rare, maybe the UK should just stick to their well tried phraseology. At least there is no way that it is open to misinterpretation.
G W-H