Edit Nevermind, I actually got it figured out.
Sorry to necro this, but I was just looking into this repo when I came across this post. I have a wordpress site and I wanted to embed my NodeBB forum into it. I have it embeded, I was just looking for a way to resize the frame automatically when I found this. I have the wordpress side of things setup, I was just trying to see if there were any examples of this forum being in the iframe as opposed to a frame being within a post on the board.
Was anything ever figured out, or were you able to make it work at all with the way you were attempting to do it, here?