My personal view would be that the avenue with the any likelihood off success would be to overturn the DAY/VFR aspect of the LAPL and have the rating added to that. Sub ICAO licence, sub ICAO rating. This was the view that EASA had in the first place.
Might upset the EAS guys a little but hey they are supposed to be representing all of GA.
I couldn't agree more.
I don't think that what is today known as the UK IMC Rating (that is, IFR in Class D-G, with no ATS service and no implicit enroute clearance, and non-radio if OCAS for good measure) has ever had the slightest chance of being adopted Europe-wide.
There are political reasons (the NAAs i.e. old airline Captains and their unions would fight like hell) but also on the practical front some countries have a lot of Class C/A and not much Class E/G.
However, if the IFR option was not excluded totally, then one could work on a modular IFR scheme similar to Australia for example, which would then offer a grandfather route from the IMCR, so an IMCR holder would enter the scheme at the appropriate point.
I can see why the IFR option was scuppered - it was done to usurp any opposition from the old Captains to the LAPL, with its GP medical and the general deregulated "sporting" nature.
I suppose one could add an IFR option later on to the LAPL but this screws UK IMCR holders who will be left without IFR privileges until somebody gets around to pushing this through EASA. And the opposition from the gold plating commercial IFR lobby will not be any easier then.