I would like to know if it is possible to delimit the screens in the editor
Above all, so as not to go overboard when creating the screens.
That is, if I create a map that is 16 patterns wide, and each 8 patterns is an individual screen, there should be a thicker mark or line or a different color.
Here is an example image made with Paint:
You can use the Major Grid for this. There’s actually a Major Grid line already visible in your screenshot, it’s just not where you want it to be. You can configure the size of the Major Grid in Edit > Preferences > Interface.
If you want it more visible than the Major Grid, you can place a grid (made of tiles, or an image) as another layer in your map, perhaps at low opacity in the background.