So while I respect your right to read what you like and post what you want to post on your blog, I have to ask: why do you think that not making the prompts an integral part of the storyline results in the story suffering? I didn’t think it affected the story much one way or another, so I’m curious.
Its being part of the prompt month when nothing pivots on any of the prompts is a disappointment but not a problem. Thing is, the fact you can say the prompts didn’t affect the story much is itself evidence in favor of if this story were not part of the prompt month, that would neither hurt the story nor disappoint any readers.
Now. In media res is a good place to start a story. It is often a good place to end a chapter. It is not a good place to end a story.
Why did Blackberries end where it did? Because as far as I can tell, SailorChibi ran out of Adrinette April prompts, and that is the only reason.