I think it would be useful to separate the protagonists from the rest of the cast by giving them a lead role instead of a main role. There would only be one or two per drama, and not all dramas would need them - for example a series with a large main cast and equal story distribution. I say this because if I like an actor and want to see more of their dramas, I want to see the stuff they take the lead roles in, but I have to check each main role entry individually to check if they're primary or secondary characters. When it can be more balanced, the difference between a main character and the lead character can be immense - some main characters spend most of their time as a mere side note. I don't go searching for shows in which a specific actor stars as the third wheel or secondary love interest after all. I'd just like to differentiate which character is at the centre of the plot.
I couldn't find this suggestion on the list, so hopefully it's not a duplicate.
