I Know this is a year after the last update but... in regards to the whole "Kreia Atris" conversation I point to this video
It proves that Kreia is able to place Mental suggestions, appear before people, talk with them then make them forget the conversation and only remember it when she wants them to/allows it. I think this scene clarifies how Kreia could have done the same to Atris
"but in those dialogue line it is implied that she actively advocated for the Exile to be removed from the Jedi order which can not be done by someone who is invisible and unnoticeable to the whole Council at that point and therefore can not interact and influence them in any meaningful way." I would like to rebut this the scene only says that she told Atris to Exile the PC ("I did as you asked" instead of "we") and as the Disciple example shows she is very capable of doing that. The way I read the scene in this context is "Kreia talks with Atris/leaves a mental suggestion, makes her forget then in the 'Quiet thing to fall scene' makes her remember"