I have asked these two questions 1, 2 that are related to spacecraft trajectories outside the Solar system. The primary reason why I asked them was to assist in my understanding and visualization (with regards to the galaxy plane) of the current and future trajectories of the 5 spacecraft that are leaving the Solar System (maybe I should've asked that question directly to start with).
It was suggested for one of the asked questions that it was
...probably more likely to receive authoritative answers in Astronomy SE than (it) might here, and galactic trajectories might not even be on-topic here since they don't reflect aspects of Space Exploration normally discussed here. But let's see what happens!
Below are the current related guidelines on what topics to ask:
Trajectory design, orbital and celestial mechanics
and what topics not to ask:
Physical sciences, such as geology, astronomy, cosmology, meteorology, except as they relate to spacecraft and space exploration
So I decided to bring this up here. I would kindly ask members of the Space Exploration community to express their opinion here (to obtain some kind of "voting"): if there would be 5 opinions expressed, and 3 of them would be that the asked questions don't really belong here, I would intend to delete them here and reask on Astronomy SE (unless there is a procedure to transfer existing question between the sites).