A Suggestion For Mission Rejection
For the longest time, Niantic have rejected missions the same way scholarship or job applications are rejected or denied. They take too long and why you have rejected is vague. The most you receive is a vague templated response. This shouldn't be the case since reasons for rejecting missions are pretty straightforward, there is a problem either or all of the following:  title/description (containing URL, names, etc, low quality) ;  image (containing person image, copyrighted, etc.),  path and objectives (too short, passphrase has a problem, etc.).
I suggest the rejection be focused on this problem on any of the 3 instead rather than the agent guessing why the mission has been rejected. This can be done like: The mission is rejected because of problems in  or the mission is rejected because of  and , possibly followed by a simple checklist of problems spotted in the mission.
But of course this is hard if there is just an algorithm passing random judgments on the submitted missions. This is very important given that you are probably receiving a lot of missions now because of Second Sundays.
Additionally, maybe take a long look at the missions criteria and refresh the requirements just like what you did on portal nominations.