Paul lumps his own Damascus road experience in with the other appearances using the same verb. If Paul’s was a vision of light, why not all of them?

This is the strongest form of the objection. Paul does use one verb for the whole list, which shows he considered his experience as real as theirs, but not that he thought they were all the same kind of event. He distinguishes his resurrection appearance from his later visions and revelations in 2 Corinthians 12, treats the Damascus event as unique and closed (last of all), and argues in this same chapter that resurrection involves a transformed body. He is not describing a series of inner experiences; he is listing witnesses to an event that, in his own words, would make the faith worthless if it had not happened.