You can do it. It's good countersignaling. But you have to be absurdly careful about writing quality. It's your job to convey to a skeptical audience that fanfiction can be transformative. You have to be absolutely brutal in avoiding language that signals immaturity -- or, better, find an editor who can be absolutely brutal to you.

My M.O., back in my college-essay days, was to read a New Yorker before sitting down to write. Inhale the style. Better yet, find some essays by Gene Weingarten, the modern master of long-form narrative journalism. Imagine what Gene Weingarten could do with HP:MOR. Then try to do it.