Eddi: strangely I find it no harder to pronounce this than xkcd.
(actually it's easier, "yay-ceedee" (which also carries our enthusiasm about the effort to implement cargo destinations into OpenTTD
) or "yassidy", compared to "ex-kay-ceedee")
The GUI should still display where the cargo actually *wants* to go, so you can extend your network according to these needs.
Maybe you should actually play it first
The GUI does display where the cargo wants to go, the detail windows of each town/industry shows the amount to each destination. The station view shows the destination/next hop of the waiting cargo, so you can see which of your routes need upgrading.-- Michael Lutz
Uh, I figured that that's what is being displayed in your current implementation.
What I meant to say was if you implemented what I was suggesting
(pax sometimes; cargo always choosing another destination if their desired destination is not connected), you should still
(i.e. as it is now in your patch) display in the detail window of the town/industry the actually desired destination.
I will follow your suggestion to actually play it though as soon as I find some time
This models a world where you compete with other, implicit transport opportunities.
I can live with this model quite fine for passengers (by foot, personal car), but not so much for cargo (cargo just doesn't move itself unlike to passengers). Cargo has to be transported by someone, somehow. And this can and imo should be done only by explicit (human or AI controlled) companies, not invisible implicit ones.
This way players who want to can live in a kind of sandboxy world where they are the only choice for industries to get their cargo transported (by playing solo and without AIs). Others that want a (more realistic (drat, now I said the word)) world with competition, can play with other (AI or human controlled) companies.
If you implement (only) the model with implicit transport opportunities, you would imo force-couple the cargo destination feature with (implicit) competition, which some players may not want?
I think there is justification for (configuration switches for) another model that limits/removes these implicit transport opportunities for pax/cargo.
With the current model, from what I've read, I would activate it only for passengers, not for cargo.
 In fact I love it! It spawned the idea in my head that (in another patch) based on these numbers actual personal car traffic could be generated between the source and destination, given there is a road connection. Now that would be sexy