This is terrific Fundles. I suggest that all fic asylums/challenges sticky a link to this post.
I had to lol at myself though. While it was clear to me that a beta was an editor of sorts, I had no idea why the term was used. I thought it was something to do with the writing they look at being the "beta" version, not yet official, the trial software that might have bugs in it! Now I know it's because the author is "alpha". Now I know why your summary of a beta is always "a second pair of eyes" - because "beta" literally is second.