There is no residual oil film. That's the point. Dry engine, that's when the wear occurs. Seems elementary to me but it is just an opinion.
So why do no vehicle or reciprocating airplane engines incorporate this kind of "spin it before starting it" technology? You would think if "dry" starting an engine, even after a prolonged period of non use, however you define that (week? month? three months?) was truly detrimental to an engine the manufacturers would be all over it. But not a peep.
I have yet to own a vehicle-- VW, Aston Martin, Land Rover, Range Rover, BMWs, Ford pickups, Subaru, Toyota--- where the manual said to spin the engine before starting regardless of any non-use interval. Hell, it's not even possible on any of these vehicles unless you disconnect something under the hood.
None of the operating manuals for Lycoming, Continental, or Pratt & Whitney powered aircraft I fly or have flown say a word about spinning the engine over with the starter with no fuel if the engine had been sitting for awhile, and it's quite easy to do this with an airplane.
One of my co-workers has a Chevy Blazer he bought new that now has 350,000 miles on it. He has the oil changed "when he thinks of it." So far the only major work the vehicle has needed was the transmission overhaul he had done the other week. If start-up engine wear was such a major bugaboo his engine should have crapped out ages ago.
So while I don't doubt that "engine wear" is at it's greatest at initial startup, I think it's a matter of degree.
Now there very well may be some kinds of engines in which pre-lube is very important. But it sure doesn't seem to be important to the typical automotive engine. And most of the engines powering the kinds of boats most of us have are nothing more than marinzed automotive engines. So if Engine-X will go for decades and hundreds of thousands of miles in a truck with no problems without any pre-start spin-up, what changes when you stick a mariniziing kit on it and bolt it to the inside of a boat? How come now it's suddenly so important to spin it over with the starter before feeding it fuel and letting it start?
Seems to me this is another one of those solutions that's in search of a problem.