As Columbo would say, "One more thing": Want to re-iterate that I don't think the logging of approaches for currency necessarily requires one to be a PIC, but does require one to "perform" the approach (whatever that means). For example, when I was a required SIC under scheduled 135, I flew every other leg as per company policy. However, I was not PIC because my 135 endorsement was for SIC. When weather was down, as it often was, it was not uncommon for each pilot to hand fly 3 actual approaches a day, not infrequently down to 200 and a half. Did I "perform" at least the approaches I flew? I sure thought so. Did I feel current to fly a general aviation airplane single pilot Part 91 in actual? Yes, although I don't think I did during that period. Maybe in a two pilot crew both pilots "perform" every approach. I don't know. We were both double ii's, but weren't acting as instructors. Acting as 2 pilot crew per 135 cert and ops specs. Where that leaves our CFI single i in the original hypothetical, I don't know, but I think he should go get his double ii!