The updates for the editor on GOG are in the game patch folders.
The editor under the GOG Tools section is the original one and needs to be patched manually with the files provided in the game patch folders.
The GOG editor version (in the patch folders) is not yet the latest version however and we're working with GOG to get the latest version up there as soon as possible

Sincerely,
Kevin
I couldn't find the game patch folders or any pak file that looks like it updates the editor.
But just the fact that GOG users have to manually update the editor, which by the way I never heard anything about until your post, and that the editor isn't actually up to date for GOG users anyway, made me realize that GOG users are second rate costumers for Larian Studios.
I am extremely disappointed in Larian Studios right now.