What functionality is missing? What is unsatisfying with the current situation?

Currently, you can only add one singular RPG Block in a field called "Associated RPG Blocks" in the "Footer Sections" part of an article. But if you want to create a building, being home to two or more types of monsters, you can currently not do that with that feature.

I'm aware, that there is an option to add the statblocks BBCode directly in the content of the article itself, but I think, that using this already existing field would make things easier. World Anvil does already support multiple entries into one field in other places, so why not add it here.

How does this feature request address the current situation?

It would allow users to add more than one statblock to one article in the field which is already made for it. Users would have to add them inside of the article itself.

What are other uses for this feature request?

Copying the BBCode is a bit unnecessary complicated. Being able to choose the monster directly from the dropdown is already easier. But since you currently can only add one monster, I can't use this feature as much as I would like to.