So I went to Content in the Dragonfall Standalone, and in the content both Dead Man's Switch and Seattle were listed as content. However DMS was not playable (in that there was no play button when you selected it, as if you chose Seattle or Shadowrun Core).
So I got to thinking. I have the base Shadowrun Returns as well as the Dragonfall Standalone, is it possible to copy some files over and run Dead Man's Switch with the (IMO improved) GUI of the Dragonfall Standalone?
The answer is: "Yup.".
First make sure you have the most recent patches for both Shadowrun Returns and Dragonfall Director's cut. Next, assuming you installed both games in the default directories, you need to copy C:\GOG Games\Shadowrun Returns\Shadowrun_Data\StreamingAssets\ContentPacks\dead_man_switch\project.cpack.bytes
C:\GOG Games\Shadowrun Dragonfall\Dragonfall_Data\StreamingAssets\ContentPacks\dead_man_switch\project.cpack.bytes
That is what makes the play button appear, but the Dead Man's Switch campaign is not quite complete yet. You also need to transfer over the convos and scenes folders (really any folders missing from the Dragonfall version of DMS) from C:\GOG Games\Shadowrun Returns\Shadowrun_Data\StreamingAssets\ContentPacks\dead_man_switch\data
C:\GOG Games\Shadowrun Dragonfall\Dragonfall_Data\StreamingAssets\ContentPacks\dead_man_switch\data
Then DMS should be playable in Dragonfall. The Dragonfall engine improvements really enhance the game and this will save gigs of hard drive space from so much redundant data. Chummer.
It works great on Windows 10.
I copied the (fully merged) dead_man_switch folder, zipped it, and backup copied it for future installs.
It also works great on Linux Mint 17.3 64 bit from the Content Menu.
I copied dead_man_switch to the Linux version of Dragonfall (Home\Shadowrun Dragonfall Directors Cut\game\Dragonfall_data\StreamingAssets\ContentPacks\dead_man_switch). Runs just like the Windows version.