>>15625966
>so that's probably why I didn't really notice the changes.
Yeah just booted up my game and I had a file I had just restarted with. Another change is that you get new cutscenes based on your D-ratio as well which are highlighted with an [SOL] indicator on the bottom when they appear. Even in the very beginning of the game. The cutscenes themselves don't give a lot of new info most of the time, just flesh out events and show events that would spoil an initial playthrough as some characters shown hadn't been introduced yet.
>Well I did think about doing that, but it's not what the game expects you to do
I think that may be the opposite, or rather both are intended uses. The game has new content with at least a couple of replays as you get access to those locked doors that respond to your current D-ratio. And with new enemy encounters and cutscenes. I think the intended way to play was to keep doing consecutive replays to get yourself to 1/4 and achieve the true ending. And you can't get a good D-ratio if you restore from a save as the game resets your progress on anything done prior to that save meaning any chests you found are no longer counted as opened. You do need to have opened a number of them for the best rating at the end of the game.
>throwing all my stuff away and starting from zero
you keep all your equipped items, Skills, Party XP, money, and stored gear across either Restart or Restore so the end goal is to grind yourself so you have the base resources to do the best possible run at the highest speed which is needed to get the true ending. But you have to do it all from the beginning without dying or resetting a save.