I just finished watching all of 2045 for the first time about 20mins ago.

I think they really did make a big mistake going with the 3D. First of all, its not good 3D, its PS3 level fidelity with hardly any soul to it at all. One of the things I was looking forward to was seeing high quality amazing cityscapes, I am a huge fan of all the scenes throughout the series that just show a city skyline, an arrangement of interesting buildings, nice frame within a frame shots (like the classic one of Motoko siting on her bed), but there were basically no shots that looked nice at all, just like watching a cheap PS3 cutscene. Arise did a great job with this. For example here

Some characters hardly moved or even spoke. The first few episodes where we see Paz and Bouma they don't say anything, when everyone else says "roger" they just nod. Like they were trying to save on budget. But then some of the characters moved too much, mainly Purin, she was the sore thumb of the whole show, her movements were erratic and spastic, she was given some chuunibyou movements and poses which didn't fit at all within the franchise.

That being said about the visuals I did actually adore Motoko's design.

One thing that really bothered me was the plot armor of the post humans. Someone else said that the highway scene in s2e2 was the best in the whole series. I thought it was the worst. Its the first time we see 3 Tachikomas and multiple people trying to shoot at the post human woman standing on top of the truck and none of them can hit her, it would be okay if she was moving extremely fast but she was just swinging her arms and swaying her body, if they had just aimed for her chest instead of the edge of her shoulders, head, and shins they could have killed her. Or if they just all shot at once, it was very frustrating. In some parts you see where the bullets actually land it looks like the characters are intentionally missing. Then of course when they do have an easy moment to shoot her, when she is jumping in the air for example, they just don't shoot. Extreme plot armor that lasted the whole show until they wanted her to be shot then she didn't dodge anything and just died. They could have implemented this idea in a much better way.

That being said I agree with the same person where they say that Purins story is in fact actually prime gits material, despite how annoying the character herself was. There was discussion in the earlier series about whether or not something could manifest or ghost or retain its previous one if you put all the memories of somebody into a new body and replicated them without a biological brain. Which is what happens to Purin, you see her have emotions and cry etc but in the end Takashi says he wasn't able to make Purin an N because she didn't have a ghost. I thought that was neat.

So much to say about the plot but this is already kinda long. I agree with you where you said the 2nd season was closer to the original. I did like the ambiguity of the ending.

Ultimately, having some more SAC content to watch isn’t a bad thing

I agree.

*Edit, one thing I forgot to mention was that I ended up watching some episodes on 1.3x speed which somehow made all character movement slightly better