I think there ist one detail in the new beta wich made me think about it. Alice talks with an unknown Voice wich has warned PACT. She calls the voice "traveler". If this is an hint to the traitor (and i think so) then there are not many Girls wich can be it. For my thoughts it could be Sola. Why? She ist the one wich fits the term "traveler" most. It haven't be the Sola wich is on the Sunrider but one of her other
personalities in another dimenson. In Solas path in Sunrider Academy this subject was the main plot. It could be that one of Solas personalities came to this Universe and support PACT to defeat the Alliance an rebuild the Ryuvian Empire. She were the Sharr and want to be it again. This motive is also fitting for the actual Sola. So why not?
On the other Side Claude can also named as traveler. She traveld a lot before hireing on the Sunrider didn't she? But I cannot really think about a plausible motive for her. Asaga and Chigara are too obviously for me and it qould disappoint me a lot when there is no good plot twist in the end. We'll see.
But if i had a whish it would none of them. Then the traitor would be an alternative personalitie of Kayto...