You can put a number [what I use] or draw a line, any color, anywhere you want in the annotate mode. I have a 6 pager and use a relatively large, colored numbers at the top left of each page. On another difficult to follow chart, I actually used the marker selection to mark each line of each verse in different colors.
Dell Latitude 13.5" 2-in-1 Ubuntu/Win 11
Samsung Note Pro SM-P900 12.2 Android 5.0.2
Samsung S7+, Android 12
Samsung Note Pro SM-P900 12.2 Android 5.0.2
Samsung S7+, Android 12