New Spartan looking for some insight on PC settings (SLI)

Hey everyone, new player here to the Halo universe. Played the game at a friends place and wanted to get it for myself. I was wondering if anyone knew if the game had any support for SLI for PC? I am running 2 GTX 1080 cards on a 3440x1440 ultrawide and pushing that with 1 card is not going to cut it. I read on a site it was listed to have support but I cannot find a setting in the game nor is it currently using my 2nd GPU so I was wondering if that was incorrect. I know SLI is pretty much dead and if I could get a current high power GPU as a replacement I would but that is not an option right now. Any assistance would be appreciated.