In The Agony and the Ecstasy movie, Michelangelo is the only possibility that I can think of, and he certainly didn’t play him as a homosexual in the movie. Perhaps Wayne was referring to a stage character?
Possibly, the Duke wasn’t questioning Heston’s acting ability but his role model status for the fans. I recall Heston telling Johnny Carson he loved acting so much that he would do it without pay.
Th Agony and the Ecstasy is a very great and underrated movie. I read Rex Harrison hated Heston and the two avoided each other on set.
Michelangelo was NOT gay, speculation on that is pure B.S. Michelangelo had an extremely difficult personality, he was volatile, mercurial etc. His large family mooched off him for his entire adult life and that made him mad. He absolutely loathed Pope Julius who was not a very nice nor ethical person. Michelangelo was a very devout Catholic, and he was not gay.
“The Agony and the Ecstasy” was a decent movie. My favorite Chuck Heston movie is (of course) “Ben Hur.”