Did more tests about the friendship gain.
First while grinding 100x working for Xavier and earning $50k, I've noticed that the girls passively earned their leaderboard score points but absolutely zero friendship points in more than 75 days...
Did another test by waiting and sleeping a couple of days. No FP gain.
So much about passive friendship point gain...
It looks quite different when the player takes action in the same locations.
Laura and Rogue in the classroom.
First, I let Laura hang in the background and didn't approach her. I only took class with Rogue. No FPs gained although both scored (A) for the cognitive leaderboard. The FPs are the numbers in the 300er range on the far right: rank|fps.
Next, I've approached Laura and took class with both of the girls. Both girls gained 2 FPs for each other.
Lastly here, I didn't took class but used the Wait action. Only Laura gained academic points. Same happens if I leave the classroom and use Wait. I had called Rogue into the classroom before, so that visit wasn't her regular class schedule unlike Laura's.
FP gain during shared training.
Double FP gain during pool activity.
"Wisdom is only possessed by the learned."