When I braise a chuck roast, it renders out pretty much all the fat. I'm good with that, the texture works for me.
That BBQ'd version in the video above, still had huge chunks of unrendered fat, throughout. I'm not fine with that, I loathe that texture.
I suspect that, in order to smoke that chuck roast to fully rendered perfection, you'd take it to the point where it was no longer particularly cohesive for being sliced or chunked. Basically, it would become pulled beef instead of pulled pork. Which is fine, and would likely make a fantastic sandwich or street taco.
But I smoke a brisket for the purpose of slicing it to perfect slices against the grain of around 1/4" (the width of a pencil). A brisket can do that because, while it has fatty and connective tissue in abundance, they're localized to certain regions within the brisket. The chuck roast just doesn't seem to be capable of the same preparation.
Still, I now want to try a chuck roast and see where it lands. If I end up making BBQ street tacos or enchiladas out of it, I'm good with that!