[Spoilers] Confused about the ITR2 last mission
So i just finished ITR2 for the first time. Upon accepting the last mission, i was given the portal device with the lid that opens on top, and to start the mission i think had to find the portal anomaly to put on top of the device. I found the anomaly, loaded the decvice, but in the end I didnt need it during the mission, and after the mission was over, I still have the portal device loaded with the anomaly. What is the device for? Is it related to the small island in the outskirts? I never did figure out that Lauri side quest, something about finding the portal on the island.