Europe won't accept the IMCr, because it doesn't work in European airspace (ie. they won't accept it any more than the CAA would accept IMCr holders in Class A).
AOPA UK's alternative proposal is that the UK IMCR should become a part-FCL Rating, whose privileges may be exercised in categories of airspace 'where so permitted by national law'.
So, for example, in the UK that means no Class A airways and only SVFR in Class A CTRs. Other EC states could just as easily decide where it may be used, for example 'for IFR enroute navigation only' or whatever restriction applies under the law of the land - not something EASA has any jurisdiction over.
Whereas the proposed Chocolate Teapot Rating would be a mere dumbing down to the lowest common denominator. The concept is an utter crock.