The Save File Repair Tool is designed to address specific issues that might be causing your game to perform poorly or crash. However, it is intended for occasional use, not as a regular performance boost. It's a one-time fix for stubborn problems and should be used with caution.
Always make sure to back up your game data before using it, and remember that it's not a guaranteed fix for every issue.
If you are considering using more than once on a save, it might be time to look into other solutions or contact support for further assistance at support@systemera.net

The Save File Repair Tool is a set of experimental settings that can remove excessive objects from your game world, which might help players overcome issues with saves that are crashing or suffering from poor performance related to excessive items. It's designed to clean up specific items that may cause issues, such as certain world objects, inactive Limited-Time Event items, and completed mission objects. 
You can find the Save File Repair settings at the bottom of the General Settings page in the game's menu. Before you use it, a confirmation pop-up with a warning message will remind you that these are experimental settings. 
When you use the Save File Repair settings, the game will create a copy of your save file  and apply the settings to it, leaving your original save file untouched. This copy will be saved with "_ExperimentalModified" appended to the original file name. You will always retain your original save, so you can always go back if needed. 
The Save File Repair settings are designed for one-time use and can only be accessed from the main menu. This means that every time you start the game or load a save, you'll need to re-enable the Save File Repair settings if you want to use them again. 
The Save File Repair Tool offers several options to repair your save file.

• Delete Non-Persistent World Objects: This setting will prevent certain spawned objects, such as small debris from loading, and regenerate them using modified spawn rates.
  
• Delete Inactive LTE World Objects: If a Limited-Time Event has ended, this setting stops related objects from loading.   This setting only applies to event items that were automatically spawned in, not event items the player crafts or receives as a reward. 
  
• Delete Completed Mission World Objects: If you've completed a mission and its related objects are no longer needed, this setting prevents them from loading to streamline your game world.  For example, this setting would remove Frozen Argon, Artifacts, Obelisks, and Mysterious Mushrooms after completing the Rails Missions, even if you’ve previously interacted with them.