It's not really the same thing as a "standalone" 'cause that might take place in the same universe as other stories or have planned sequels.

Ah, that makes a lot of sense. So there might be a sensible reason for them not wanting a whole series of stories.

People are dumb, basically. I get that some of the requests sound ridiculous but I also know that sometimes all you want is a certain kind of story. But yeah, make sure you ask in the right place. It's not hard!