Bob,
Mine did not come with a plug , but did include start adapter. Difficult to tell its been run, until you find the screw head/washer marks on the mounting holes - other than that there is no sign, it was extremely clean, minimal oil film. From the stiffness of mine I would guess factory run is brief, and can be ignored from the run-in point of view. Took a little persauding to get my starter to turn it over, but once turning and adding plug lighter it fired right away. Has never needed a second start attempt yet. More bench running this weekend.....
jp