It's not whether this or any other modification provides a speed advantage; it's whether the Class intends to enforce Class Rule 1.5. I'd suggest Michael L and the measurer simply reinstall the $40 cowl vent (and deck plate, which by the way is no additional cost) in order to return their boats to original condition.
It should not be easier to get forgiveness than permission, but I suppose they could still request a ruling, particularly if there is evidence that a reasonable number of J/30s were delivered without the vent. Then the question would be how does the measurer obtain a ruling on a boat in which he has a vested interest given CR 4.4? And before you ask, no the measurer can't make a ruling on Michael L's boat and then turn around and apply it to his own.
