Having a toggle doesn't make it a better feature. You like to use save exploits, but you don't want them available because you can't help yourself from using them? Learn some self control.
You can only toggle it once when you start the game, after that it's set.
But yes I do need to have some better self control.
Even so, this feature would hardly be any difficult to implement.
Add a new model (say a machine that looks kinda like the regular computers in FO3 and name it "Save-Log" or something), code it so that "save game" is take out from the menu and can only be activated when you're at this new model.
I don't know exactly how a game is developed but I'm guessing this would take a day or two to actually add.
It's easy, practical and optional.
I see no problems with it.