Wouldn't it be more optimal to go for Materialists instead of Spiritualists if one is relying heavily on droids? Then upgrade them to Synths and do the Synth ascension. Sure, a bit less unity that way, but more science (directly from ethics and via their special living standards) and more influence because of a super happy faction, I believe you can't make Spiritualists happy with robots without a hallowed world, which if you found another gaia as Life Seeded, it would be better to colonize it with your main species than to declare it holy.
Well I did several game in materialist too but since i prefer to pick psy ascension i prefer to go on spiritualist! I Need to rush tradition and ascension perk as fast as possible since i play with life seeded i can't go inward perfection + agrarian + adaptability wich is actually the best way to rush tradition i think! So I chose spiritualist + pacifist + agrarian do still gather a lot of unity! Its a bit slower but working very well.
You are right Materialist is a great way to play lifeseeded too and I did get even in tech with FE within 150-200 years And you can do mass colonization even faster with droïd! But actually in the way i play i do control my development and don't need more thant 2-3 Mining planet After that i go full habitat ringworld because I'd like to play a bit rp and my species don't want to much droïd... That's all still working very well but start is a bit slow! Actually playing with 5 advanced AI in difficult and i finnaly get even to them in 180/200years with spiritualist and bit before with materialist! it's way more funny when you are not always the strongest empire in the galaxy anyway or game becoming boring... Life Seeded can be play in many ways and its more malus than a boon after all so it's make game more interresting and force you to be smarter in your choice! That why i love Life Seeded but it is not the most efficient way to play this is 100% sure, but i think one of the most interesting in my opinion! Gaga Build is way too strong it may be fun with full Advanced AI in insane difficult but i tryed once and its just overpowered once you understand how to optimize it... I think it's going to be nerfed because adapatibility giving 1 mineral for farm so farm product food/minera/unity i way too much and the cumulative Unity bonus of adaptibility up to 30% is way too much too my guess but we will see. This is just my opinion and people may think differently, we all have different way to play after all!