I don't know how feasible it would be, but an idea I just had would be a way to create sub-sections in individual stories (that could be named "chapters" to keep with the theme).
I think this would definitely help stories with a lot of roles, as having to scroll through them all is rather daunting for people. But if, for example, a Marvel Comics story was able to group roles into "chapters" such as "X-Men", "Avengers", "Spider-Man", etc., it would help increase engagement, I believe!