As for a legal challenge should all fail I would imagine this would be brought by AOPA and not financed by an individual.
As an AOPA member I would be veyr unhappy if my membership fees were used to fight a court case on behalf of people who have had over five years to convert licences to meet the regulations of their home country and refuse to do so because it is inconvenient or to much like hard work.
I am dual licenced so happy to take over any of the job vacancies that will arise from those who refuse to comply.......
