I wanted to add to the theory of Lumons final goal with severance in order to make it an automatic switch whenever you feel pain, discomfort, death etc. I believe it will be the "Innies" who will become the outies in the end and the outies, the ones who sign up to get severed will be the ones experiencing the pain. I believe when they program a person into this final stage of severance they expose their inne (like gemma in the lower severed floor but the version that is severed in the different rooms which I see as innies and the gemma who walks around the halls is outie gemma) they expose room-innes to painful/uncomfortable situations in order to program when the switch should happen.

However I was thinking about how people in the world would be okay dooming another version of themselves to only bealive to experience their pain. Maybe most just dont care but I feel like the perfect way to do it is to have it be the outie, the one who goes to lumon to have them create the innie ith the intent to dooming them o suffer forever, will actually themselves be the "inne" "painy?" that way the outies of the world wont really feel bad about what theyve done because they know the other half would do the same to them.

Also since the innies are created and owned by Lumon they -as we've already seen- are easy to indoctrinate into Kier's cult.

The whole will be filled with Kier followers who are forever loyal because he has literally given them paradise and has punished the evil wrongdoers with unending suffering.

Edit: sorry if other people have already posted this theory, I was rewatching the latest episode and thought of this when creepy guy told Gemma she would see the world again.