Good morning, Tony.
Interesting update. After booting up Unity today, I noticed that the dialogue to dialogue linking was now working, despite me not changing anything in either Articy nor Unity since writing my posts here yesterday. (I suppose, not unlike how rebooting a PC can mysteriously fix problems, Unity might be the same way.)
However, while dialogue to dialogue links are now working, using Articy's 'Jump' node to move to a different conversation is still broken. I'll include some screenshots from both Articy and Unity, showing a Jump Node and how it correctly links in Articy, but the 'Links To:' property in Unity (after the Articy export) is blank.
Absolutely no rush here, since I'm doing playtesting from the early parts of the game (this issue is only occurring in the latter part), and I'm also distracted by keeping an eye on my demo in Next Fest. Enjoy the Tribeca Festival!