A valiant attempt I also saw the original stage production in LA in 1978/79. I was likely the only Anglo in the audience, which was itself an experience worth buying a ticket to. I would have gone back several times if I had had the money.
Olmos was featured in the local TV commercials for the play and was riveting to watch. That commercial could be re-released as a short. In the theater, you could NOT take your eyes off him.
I have seen the film several times and own a DVD copy. While there are some cringe-worthy moments and some obvious "staginess", the film does credit to the original vision and is worth watching.
One should never watch a work of art in an attempt to learn about history, or science, or anything else. Art is art.