Yes, you forgot that (my wording may have been ambiguous, sorry).
One idea: It may be easier to see the separate lines if some of them are not rectangular again. What do you think about making the blue lines direct connections (and maybe have them start from the same point on one continent)? Same regarding the brown lines on the continents. That way you should win a lot of space to add the missing lines.
And maybe the rectangular lines are nicer if you make them curves (or shaky freedrawn lines, hehe)?
Well, just ideas to play around with. Thanks for your work so far! And very good idea to add a legend regarding the different line colors!