Writing advice?

So, I am generally not a fan of the thing where people kill off one half of a canon couple so they can get their ship together. I'm wondering if what I am contemplating doing is too close to that, even if the character is an original character, or if it is in general just too convenient for the plot. I already have a great beta reader for this story, but I just wanted more input on it...it's a general question which doesn't really depend on knowledge of the fandom.

( More details (contains spoilers for my Flight of the Heron poly fic, if you care about that) )