the user would be plased not have to relocate his save files
Huh? save game locations are to be put into a user specific folder, not the game folder.
You seem to reinvent the wheel a lot. As a rule of thumb, if no one else is doing something or everyone is doing things a certain way, there usually is a reason. It might be a stupid reason, of course. Or a limitation of some engine.
Like in this thread, the overly big games. The offenders are usually visual novels with heaps of pictures. If those are lossless output of their rendering chain they are needlessly big and could be made a lot smaller. But here we go back to the reasons why I would not trust a single dev with an updater companion. It is different skills. Some of the devs are not capable or aware how to make their games reasonably small. Or they just do not care. Or they do, but in a different way. They hear lossy compression and fear for their art to be diminished, or so i imagine.