Yes, I did! As I've mentioned, I went into Anabaseios petrified they might "ruin" what I liked about her in Abyssos, and while I understand reservations about the influence of the Heart of Sabik, I truly did think her presentation was overall a wonderful surprise, and the almost emotional anti-climax by the firm assertion that no, there is nothing there - it almost felt like there was a certain awareness of the expectation of how a typical abusive mother trope might play out in media - was a delight. And I do want to say I adore her not just from the perspective of being a loveless mother and unrepentantly evil woman - she also kept that almost businesslike demeanor that I thought I picked up in Abyssos that seemed really interesting, and the sort of raw, earnest passion for science. Athena perceives herself, and believes she conducts herself, as a true professional, and that also has a certain delightful appeal.
(I sort of want to mention another part of what I think made me feel Athena's integrity as a character stayed intact even with the Heart of Sabik thing - the question of Sabik's influence is introduced only partially through the raid, and alongside it is Erich wondering and questioning his father if it was possible things could have been different if not for the space rock. It's explicitly a question raised, to be answered later, because he doesn't get one at the time. That ambiguity still gnawing at him is exactly why he goes out of his way to question Athena in that last sequence, fishing to see if there is anything to hold on to, any reason to think things could have turned out differently, at least for their fundamental relationship as mother and son, if not for Rocks. And he gets his answer, and the matter is settled. And the answer is no. That's a subjective reading, but it's genuinely the one I got, I think.)
As for the symbolism - I think the imagery specifically in that regard was mostly resolved in Abyssos itself with the Hephaistos/Lahabrea arc, and the way she "poisoned" him to the point he had to break himself in half to keep her influence at bay. (And also that brief stint of invading Erich's thoughts to brainwash him via Hephaistos, arguably, since the brainwashing revolved around love for his mother.) I was actually very impressed even at the time with the relatively understated use of the symbolism, because it wasn't in your face - nobody stared into the camera and said "alas, my love for Athena was unto like a poison upon my soul" - and was therefore presented in a way there was that special joy when what was going on with the background visuals clicked into place for me, the recognition of a cohesive theming. But it was also consistent and prominent enough that it felt like, once you noticed it, there was also no mistaking it. Wonderfully executed.
But literal story aside, the symbolism is most interesting because it reflects, moreso than anything silly like "Athena magically brainpoisoned her husband and child!" - the dynamic of a toxic family, the struggle of the feeling of "poison" or "parasite" that clings even as you struggle with lingering feelings of affection, even as you know you "shouldn't" feel such things - as Erichtonios('s memory shade, yes, it is contrived, but for the purposes of the narrative and emotionally, still obviously meant to simply be a Cheat-Don't-Talk-About-It-But-Otherwise-Authentic version of Erichtonios) continue to do even in Anabaseios. Or, even more poignantly, even though we come to understand that Lahabrea truly loved Erich, Athena's "poison" was so horrific and all-consuming to their family that it warped their relationship that as a consequence of her abuse, Lahabrea ended up in a place where he also felt he had to, in a way, become an extension of his son's continued mistreatment in order to protect him from her.
Rot is a specific word used by Hegemone in her encounter (and part of the imagery invoked by Agdistis, too!) and it's really apt, because Athena's shadow rots away love that should have been something to treasure, should have been one of the forces that most supports a person, on multiple levels. And it doesn't destroy it, is the thing - it twists it. The love Lahabrea had for her, the love Erich had for her, and even the love between Lahabrea and Erich. It all rots and curdles under the weight of her toxicity.
Anabaseios left behind the poison symbolism a bit as a whole in favor of the heaven/helland Venatsymbolism, but Athena's Theos form is still insect-based, so it also wasn't entirely abandoned. And the final exchange between Athena and Erich could probably best be described as, ah, "venomous." But Erich's counter to Athena still reflected that consistent note of her seeping influence that corrupts and ruins, even in ways she didn't actually want. But while Erich "overcame" her to reclaim his own agency, and even declare he had found his own family, that lingering element of him manifesting again to stare at her as she died with that last bitter exchange...
I'm not sure how to put it. It was a good, complex balance. He overcame her and it was truly triumphant, so I'm not trying to and absolutely don't want to undermine that, but it's also not like he also chose to "walk away" in totality either, if that makes sense. Erich has a right to be venomous to his mother, to linger and steep a bit, and I'm glad he was allowed it. (He can have a little poison, as a treat.)
It was all really great. My wife.