It'd be bad compared to a BL novel, sure, but it would be a whole lot of fun to write, which is the point. And "The End" was similar, and that turned out quite awesome. What was lost in polish was gained in creativity.It would be godawful. Novels take planning and strategising. If you wanted to do this way rather a collection of linked short stories.
But "The End" is asleep for lack of interest, and interest is my main concern here as well. On the format, I think it'd be nice to decide the initial idea for the story before we begin. "The End" had no 300-word or 1-character limits, but I do think those are very good ideas to make things a bit more organized. Maybe also a time limit such that, if someone doesn't write their part within five days, someone else can take over.
Anyways, I'd be up for participating for sure.