GoG Version Functionality

A few weeks ago I bought the GoG version of Offworld Trading Company so that I could play it with my friend.  We have waited to play this game together for a few weeks now and have yet to see any word on Cooperative coming to the GoG version.  Is there a timeline for when the GoG version will have any of the features of the Steam version for multiplayer?  The GoG version feels like a paid demo right now, is there any way for me to play this game cooperatively without re-buying it on steam?