You can easily implement this feature:
1. Create a new package
2. Add IDEIntf to the required packages
3. Add IDECommands to the uses clauses
4. On IDE startup, start a timer, preferably a thread timer so you don't interfere with the IDE, when the timer ticks just call:
uses IDECommands;
//...
IDECommands.ExecuteIDECommand(Self, ecSaveAll);
//..
5. You can also create a dialog where the user can set the interval, or disable the feature, etc...