Naclador: The Problem with Adding the Twitch Stuff with the Editor is, you have to collect those Items ingame after adding them and the Option to collect Twitch Items is not existing in the GOG Version.
I Really like GOG and DRM Free stuff and GOG is always my first choice.
But I rally love No Man Skye and that's the reason why I had to buy the Game during a sale on Steam too.
Now I can transfer my Savegame to Steam, get the Twitch stuff and then transfer the Safe back to GOG, That works fine, but I would definitely prefere to have the ability to connect my Twitch Account with GOG and get the Twitch Drops directly.
I'm not sure for how long, but the menu-option to claim twitch-drops is currently in my game, same place as the Steam version.