This leaves the US IR holder who does not fly IFR reguluarly in a bit of a pickle by having to bag lots of instrument approaches and having to pay the practice approach fees at various fields.
Not really, luckily the CAA gave me an IMC rating for free, which is valid for two years. Even if my FAA IR were outside the 6 months, I could still shoot the approaches, in IMC if I wished, using my IMC rating. Not only that, I can use the various FAA approved sims around the country should I wish. Then every two years I do an IPC while in the USA, and get my FAA IR zero timed, my IMC renewed....
Anyway, its not an issue for me, I go to the USA normally twice a year or more....