That's kind of why I asked whether
@M.Sove was expecting some kind of benefit.
Back in 2012, the Chief Counsel was asked whether a safety pilot is required to pay a pro rata share of expenses because the safety pilot is receiving "flight time" compensation. The specific answer was
Section 91.109(b) prohibits a pilot from operating a civil aircraft in simulated instrument flight unless a safety pilot is present. As such, both pilots are required crewmembers during the portion of a flight that is conducted in simulated instrument conditions. The safety pilot is not required to pay a pro rata share of the operating expenses of the flight regardless of whether he is acting as PIC since neither individual is a passenger.
The safety pilot could offer to pay a pro-rata share of the costs of the flight, but there is no requirement that he do so, and not doing so is not a violation of§ 61.113.
It doesn't go quite as far, but the overall tone always sounded to me like, "when it comes to two pilots sharing a flight we really don't care what you do." And my take is that it especially applies to the very common requests to locate or to be a safety pilot.