Rachel has raised a very important point. God does not need to investigate in order to figure out who is saved and eligible to spend eternity with God, and who is not saved. God knows.
The so-called Investigative Judgment (IJ), is not focused on God in that sense. The plan of salvation, in its beginning was focused on the false charge that if God actually gave His creation freedom of choice. The Investigative Judgment is an examination of the record of the candidates that assures the created, intelligent, beings in the Universe that they have freely chosen to spend eternity with God and that if they are allowed to do so, sin has been so eliminated that they will never choose to sin.
In it the Universe that needs to have this assurance.
God does not. God knows.
We who it is commonly stated are being judged, do not need to fear for our salvation. It is fixed and certain. With the end of the IJ, the Universe will also have that assurance.