When I originally read 61.57(d) and it says "a person who does not meet the instrument reqs of (c) within the prescribed time, or within 6 mo after the prescribed time, may not serve as PIC under IFR in WX less than the VFR mins...." and I had a brain freeze and thought that during the grace period I was able to act PIC. I then reread (c) and it is clear that I can't. So vague would be my logic on this, not the reg.