I would simply argue that the “offline” editing is a people-problem and hence van not be solved using automation. People shall find a way to break/bypass the automation/system.
The only “offline editing” that I allow on human text documents is having people add comments. So not editing, no automated merging.
For “offline editing” that I allow on automation (source code) is GIT which intentionally does not pretend to solve the merge, it just shows revisions. The merge is an action supervised by humans or specialised automation on a “best guess” effort and still needs reviews and testing to verify success.
The only “offline editing” that I allow on human text documents is having people add comments. So not editing, no automated merging.
For “offline editing” that I allow on automation (source code) is GIT which intentionally does not pretend to solve the merge, it just shows revisions. The merge is an action supervised by humans or specialised automation on a “best guess” effort and still needs reviews and testing to verify success.