MachX: This makes no sense whatsoever. If after patching, the base game has become the basic patch, then how does one play the game without the patch? By uninstalling the patch?
I think in order to start the game with the patch, you always need to start it like this:
Vampire.exe -game Unofficial_Patch
Which is what GOG launcher probably does according to their Json file?
If you don't use -game Unofficial_Patch I think it should run in "stock" game form? Though I never tried - I simply see no point to not use at least the basic patch.
UPDATE:
I just checked. The basic patch game lists both patched and "legacy" options in their launcher json file (goggame-1207659240.info)
So I think you should see both options somewhere. The difference is like above. One launches Vampire.exe -game Unofficial_Patch and another launches simply Vampire.exe
To sum it up if anyone will be looking into this again:
* To play the game without unofficial patch, use the version with basic patch and legacy option there
* To play it with basic patch, use the version with basic patch (regular option there)
* To play the game with plus patch, use the version called "unofficial patch".