I've read that as it stands now, the fanatical purifiers have a modifier that makes them very likely to be advanced empires. That means there's a modifier that could be accessible for mods to make different types of empires more likely to become advanced empires, so you could activate a mod that makes the empire type of your choice more likely to be an advanced empire... but there's no guarantee that empire type would be spawned, and no guarantee they get an advanced empire 'slot' if they are.
I could see your suggestion being good if they get around to a patch or DLC where they add more general customization to starting settings. There's a lot they could do there if they take a look at that section of the game.
Also I guess you could design an empire that meets your specifications, set them to force spawn in your game, and have a mod that sets their personality type to be more likely / guaranteed to be an advanced empire. That's something you can achieve with modding to tide you over I guess.
