Hey, The Dual GPU systems are definitely coming to Maximum Settings but as a Speciality Category. If you check out the fantastic videos made by Minea with 2 RX 480s with Crossfire, it can more than double your FPS on supported games. Unfortunately, the support for these games are limited by developers and not many current AAA titles support this feature.
https://community.maximumsettings.com/d/117-maximumsettings-com-cloud-pc-battlefield-4-max-2x-rx-480-in-crossfire
https://community.maximumsettings.com/d/116-maximumsettings-com-metro-2033-redux-2x-rx-480-8-gb
The crossfire and SLI options are being tested and will be available soon, however it is important to know that not all of your games will be able to benefit from dual GPUS. However it is still very cool, and definitly does improve results in older titles. Also, its the ultimate bragging rights, and would be an experience that i wouldnt be able to have without maximum settings 🙂
https://amdcrossfire.fandom.com/wiki/Crossfire_Game_Compatibility_List
https://www.pcgamingwiki.com/wiki/List_of_games_that_support_SLI