If you think 450MB is normal for a savegame then you don't understand how a savegame actually works, and there's a handful number of games that actually have this abysmal size (yes, it's abysmal, there's many games with more complex addressing that are smaller than that). All coordinates, inventory, name it, you can fill a ridiculous small database for that, heck a sqlite would laugh with hundreds of information like that by hitting 10M if much.
And you're thinking only about your savegame (or into a desktop side perspective), I'm talking about hundreds, thousands of savegames, where deduplication could save 90% or more of diskspace on the server so limiting to 200MB wouldn't be necessary.
Deduplication isn't useful to the savegame on your desktop, it's useful for the server side.
