Again like I said, as a private plane owner flying for yourself you have no reason not to put your plane on N-registration so you can get the FAA-IR. Problem solved.
But a Modular IR ? Completely insane, apparently these guys have no clue what it is to fly in the system, single pilot and under heavy IMC. You have to be current and that means full commitment from your side, there's no modular partial way possible. Period.