When Dragonfall was released, fans quickly found a way to play the Dead Man's Switch campaign from Shadowrun Returns in the new Dragonfall engine (by copying over some files), e.g. as described here.
I tried the same for Dragonfall in the Hong Kong engine, but it didn't work.
So...is there a way to achieve that?
Not yet.
Per my research and after trying for 2 hours to make it work, I came to the following situation: After copying the ContentPacks directory from Dragonfall to Hong Kong, the Hong Kong engine shows the screen with the story installed. You can even create your character and start playing.
The problem starts when you try to grab something (like a drone or a weapon). The game will bring the popup screen to manage the item (take or send to stash). It seems that the new engine handle that differently than the previous engine, causing the game to freeze.
It is possible. You have to go to the data folders of DMS and DF and then to the StreamingAssets folders and then to ContentPacks. Copy DragonfallExtended (If you have DF standalone) and Berlin to Hong Kong's ContentPacks folder and copy Dead man's switch and Seattle from SR:R to the same place. So far I haven't been able to get past the opening of Dragonfall as when you choose your weapon, it pulls up the manage/take screen from HK. Normally the weapon is added directly to your inventory so I am guessing that the DF campaign can't understand the menu. It's not crashing/freezing the game, however when I click take nothing happens.
