So after 400 or 7000 years she gets to automatically reset herself back on earth, but will she even remember what life on earth was like after 7000 years. Sure after 400 years you might still have some vague recollection, but after 7000? Seems like a pretty big plot hole. The alternate option of wiping her memory is also a bad option since it will mean that everything that occurs in this manga is completely meaningless in the long run.
Sure you stopped society from being reset for a bit, but God doesn't allow you to bring progress to their world. In fact he actively prevents progress from occurring, so the only thing you can really do is sit around with your harem of bishonen for 7000 years in a world that won't progress or change. Then, after all of that waiting, the big reset happens at which point you are placed back in your own world where you forget about everything that occurred with your one true love/fated person. You also have the bonus of not being able to fall in love with anyone for the rest of your life on earth no matter which option you chose. If you remember you've lost your 7000 year companion. If you forget, your personal feelings were already manipulated by the God of another world so that you'll only truly love your fated person. Seems like a fucked up situation. Then the cherry on the crap sundae is that if you remember you've lost all of your healing abilities. Over the course of 400~7000 years there has to be several medical advances that you will learn that you could apply back in the real world, but ultimately you won't be able to do any of them since you won't have your magic any longer. Leading to situations where you'll have someone die in a medical situation (since I'm assuming she would become a doctor) that you know you could save if you could use your true powers. Of course, once again none of this matters if you memory is wiped. It all seems like a big waste of time and effort where the only end goal is to entertain a bored God.
On the bright side, at least she now has a harem house with member #1 Kumon at her disposal right now. Maybe her big brother that was mentioned in chapter 30 will get thrown into the story as well at some point. Who knows.