As much as I can understand your reason -- I would advice every single creator to
not do so.
Why? Because I've seen this in so many other threads where "update-only" files are available, that the majority of users is unable to follow the most simple instructions on how to use those update-only files or they are just not "good enough with computers" and will screw up their game installation.
As a developer, you want to keep it as simple as possible for users to play your game:
download, extract, run
And not
download, extract, copy-to, overwrite, run