The following will cover information on the easter eggs that I think are possible clues.
FORERUNNER
In the room before you activate the cryptum (the level before the ghost ride) there are hexagonal shaped pedestals. The thing that I can’t grasp is the square.
Any ideas about the square?
Shutdown
“smash enemies asunder” (as the clue said). I’m ASSUMING it’s a hidden gravity hammer. “In the requiem of the beam, a treasure not first at seen”. An idea could be that the blue beam in which the gondola flies through there is a hammer in the beam.
Infinity
“Wait for the call of the cobra hunter”. The first clue slightly gives it away. A COBRA HUNTER is a mongoose. The prey of a mongoose is a cobra. So the call of the cobra hunter may be the mongoose honking. “Before contacting your stalwart comrades” (the room before seeing Lasky). So that might be the room with the easter egg in it.
This is all the information that I can find so far. Hope this helps:)