Alright, did a quick paint over of the overview so we can make sure we're all talking about the same thing
Current spawn points are numbered in order, and colored depending on the team that owns them. Both teams shift from their first spawn room to their second when the second point is captured.
Capture points are colored in purple Xs, and numbered.
Light green numbers indicate potential sites for other spawns, with the light pink arrows showing the exits.
I'm thinking of moving a spawn room out of the train station (currently Blu 2) and making it a cave exit at green 3. This would make it
harder for Blu to attack the 3rd point, since it is not as close as the current spawn, as well as spawning them behind the cart, and in a safer place than they are now (one time I saw 8 engies build sgs outside of the door). This new spawn would have two exits, a lower one which exits at the height of the track, and an upper one which exits closer to the door that leads into the blue building at the 3rd point.
Green 4 would become active once the third point is captured, there to attack the final point. This would exit into the blue building, where players can go left across the river and either up stairs or the normal way by the track. Moving a spawn to Green 3, and adding 4, means 4 is a significant move up.
Green 2 is just an idea, adding another spawn right when the first point is captured. I don't really want to do this, since as you have said, a ton of spawns in payload is bad, and I don't like it either. However, it is pretty much the only place I could add on there. Hopefully further testing of the new side path will determine if its needed or not.