I thought about something like this for Materialist: "AI Aware".One solution could be to have a "followers of the worm"-faction which could have followers from all ethoi but would mainly recruit from the spiritualist ethos and could thus compete with the standard spiritualist faction. They would have different faction goals to the standard spiritualists though where they might consider tomb worlds to be holy places, like loop buildings and black holes and some other things, some of which might coincide with the goals of the spiritualist faction.
The benefits of this would be a nice faction representing your choices in the game that would solve the problem that I have with loop followers hating you for inhabiting tomb worlds, offset the penalty to happiness from buildings like the spiral feed power hub which would actually make it a worthwile choice and show some of the religious conflict that probably would arise between the followers of the old religions and those of the Worm.
Basically that is a Materialist empire, that will NOT reserach or at least use AI because they know how dangerous they are. Everything Robots would normally give them (I asume Ethos atraction and Materialsit happiness) would be coded to apply without robots as long as they have that civic.
They are hardcoded to not allow Robots, not have increase weight on Robot techs (or only improoved up to T2). They may or may not be able to go the Technological Ascension Path at all.
Marterialsit FE would consider the "nice guys" for actually forbidding AI. Naturally the Materialist FE would be the first guys to pick that Civic. If not for this itteration, for the next one it would be nice.
A single country flag or civic could easily change wich way happiness and ethos atraction work.