Good news! With a little more effort I found my altered RotJ script incorporating dialogue from the Radio Drama. Here are the scenes I suggested be altered, the new dialogue being in bold:

Too late. The Wookiee has already pulled the animal from the
stake. SPROOING! The group finds itself hanging upside down in an
Ewok net, suspended high above the clearing. Artoo lets out a
wild series of beeps and whistles, and Chewie howls his regret.
Their bodies are a jumble in the net. Han removes a Wookiee paw
from his mouth.

THREEPIO
One would suppose a 220 year old Wookie to have learned a measure of self-restraint.


HAN
What are you telling them?

THREEPIO
Hello, I think... I could be mistaken.
These creatures seem to call themselves Ewoks. And I do believe they think I am some sort of god.


Suddenly all activity stops as LOGRAY, the tribal Medicine Man,
comes out of the big hut. He examines the captives carefully,
goes to join Threepio, whose throne has been placed on an
elevated platform. A larger, gray-haired Ewok, CHIEF CHIRPA, is
examining Luke's lightsaber with great curiosity.

THREEPIO
As I understand it Master Luke, the forest has been invaded by Stormtroopers. The Ewoks presume you to be enemies.


HAN
What did he say?

THREEPIO
I'm rather embarrassed, General Solo, but it
appears you are to be the main course at a
banquet in my honor.

Shot of ARTOO.

THREEPIO
And you Artoo are to be reclaimed for useable scrap.

Another Shot of Artoo-he is displeased.


At the end of it, the Chief, Logray, and the elders confer, then
nod in agreement. The Chief stands and makes a pronouncement.

LUKE (OS)
What are they saying Threepio?

THREEPIO
The Ewoks want to know where they fit into the story Sir. Myth and life are strongly intertwined with Ewoks. If I make them part of the tale, it will in their minds make them part of the Rebellion”

LUKE (OS)
Do it Threepio.

Threepio says more Ewokese, including them in the story.

That strengthens the Ewoks characterwise I think, giving them reasons for their actions. Also I thought it would be nice to throw that reference to Chewbacca's age in there just for the fun of it.