The other occasion where Marquand put his foot down was during the Throne Room fight with Darth Vader. Luke has a moment where he jumps away from the confrontation with his pops and ends up with the high ground, standing on some scaffolding. Vader has clearly had enough of this high ground business and uses the Force to throw his lightsaber up and collapses the whole dang thing, spilling Luke to the floor below.
That was another no-go from Marquand. He explained:
“The other thing I wouldn’t let him do was in the Emperor’s Throne Room, during the fight on the balcony. It collapses. And Luke falls off and goes skidding way down. I wouldn’t let Mark do that one either. But apart from those two, he does everything; his own fights, everything.”
As much as I love it when actors perform dangerous stunts, Jackie Chan-style, I totally get why a director would say, “You know what? Maybe the star of my movie shouldn’t slide down a collapsing walkway in a long shot where you don’t even get a good look at their face anyway.” Marquand didn’t mention if Hamill put up a fight over these scenes, but even with Hamill playing Luke at his most powerful I can’t imagine he wouldn’t agree with the director in these instances.
You can also find this interview, and many other incredible behind-the-scenes stories, collected in J.W. Rinzler’s book “The Making of Return of the Jedi,” by the way. His whole original trilogy series of “Making Of” books are must reads for any “Star Wars” fan.