Been playing with the latest Anno 1800 dlc (empire of the skies) and I would like to point out some bugs that were not mentioned in your known issues on (Trello)
1. You forgot to resize the different skins of the old airship "Boreas" to 90%
2. You forgot to put the airship ornaments in the cultural tab of the buildings menu (it's only available if tiers category is chosen)
3. Maybe that's a design issue, but in the scenario Clash of Couriers which is supposed to challenge the player into building a network of mail delivering ships. It's easily possible to get gold and all the 3 badges by only settling one island and having a single mail route delivering mail back and forth between the main island and the second!
4. The airships would rather wait for a busy air platform to unload trade cargo rather than use a free pier nearby, putting lots of strain on the slow (2t/secs) air platform. (An option to make the air platform exclusive for mail would be useful, or for the airships to chose a free pier to unload/load cargo).
I hope these and the other known issues would be addressed soon. Great job on supporting Anno for so long. And congratulations for what seems to be the best Anno so far.