Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - General Two original games not included in physical CE?

1. no. That would require logging into a Steam account, which would require registering the game on Steam, which GOG does not support. Purchases from the Larian Vault may include a Steam key, but the DRM free download and Steam version would still be separate (if you installed the DRM free version, you could start the Steam install, pause it, move the DRM free install to the Steam folder and verify files to minimize the download).

2. not officially. It might be possible to get it working if you add/edit some registry entries, and maybe make adjustments to the install folder name, etc.