Hello. Long-ish time wiki reader here.

[Rynn]

I was more asking if there was somewhere I could look for more detailed information about s>3 transapient /archai beyond what is covered in Encyclopedia Galactica, since my idea mainly involved a tribemind forming clade that effectively ended up turning into an archai. The EG articles don't really have much information about the higher toposophic levels for in-universe reasons, so I was wondering if there was anywhere in the forum I could get more information about them.

Welcome to the forums! I wrote an article like this once.

https://www.orionsarm.com/eg-article/55955128ec815

In working out the details for it I stuck to the tribe mind being capable of reaching S2. Reason being that S3 require about a moon’s worth of material as a processor. If the idea is to have modosophont (I.e human level) sophonts combining to form the mind, a moon’s worth is too prohibited. An M-Brain masses about 1e21kg. Given that a typical brain weighs a little over a kg, that means we’d need to connect at least 1e21kg of modos together. Likely more because modo brains aren’t as efficient as processing per unit mass than technology.

That’s more modos than exist in the setting. The idea could work still but you’d have to have to tribe mind merge, go virtual, or otherwise radically alter itself to cross to S3. Archai begins at S4.