"John T" wrote
In a single pilot airplane, it is fine for the person to log PIC even
if he is not current, as long as there is someone current on board
Not really. I think the confusion stems from the use of "PIC" in two
similar but logically separate functions. There's the guy in charge
of the flight and there's the guy manipulating the controls. Think of
it as "pilot in command" and "pilot in control". They're both PIC and
they may both log PIC for the same hour. (See "safety pilot".)

The Navy solved the problem very simply.

The "assigned PIC" is always the PIC (and logs PIC) no matter where
he/she sits or what he/she does.

The pilot manipulating the controls logs "First Pilot" time.

The pilot assisting the "First Pilot" logs "Second Pilot" time.

Actually, during my stay in the P-3 Navy, the term "Patrol Plane
Commander" was used in place of the FAA term "Pilot-in-Command".

Bob Moore