Etiquitte for requesting unpopular slash pairings?

Hello, I've never used Skeb before and I was wondering if it's mostly used for art of original characters, or if it was acceptable to request ship art? Specifically, yaoi of two Kingdom Hearts characters that absolutely no one else ships. I know artists can reject a request if they don't want to draw it, but still, would this be considered rude? Has anyone here used Skeb for fanart or ship art before?