As you said, SuzSLO as someone who picks up quite a few UFOs, there are usually reasons on why they are not done. The nice thing is that I am willing to undo the work/time of someone else that maybe I'm not willing to do on my own projects so it all works out.
Those wrong sized setting triangles is a common issue and I agree with the others, cut it off smooth and let the points land where they may and either finish like that, or put on a border of something that is vaguely coordinating.