That twist about the cat really didn't do it for me, and it again played with the idea Bart is bone-dead stupid. Were it not for the need to pad out the running time, the episode should have ended right at the treehouse when Lisa reads the diary...failing that, they should have saved Lisa's confession in the third act as the moment to reveal what the twist was.

We know from Flander's reveal at the end Edna cared about Bart, so the diary entries still make sense even if you take out the cat.

I liked that Lisa's whole motivation was due to her not wanting Bart hurt, but they had an opportunity here to subvert expectations and not have a big twist ...they could have played with the audience a little more and then ended the episode with the simple fact Edna meant every word of it and Bart kept ascending.

Why do I say this? Because I just completed a fandedit which removes the entirety of the twist

I thought Edna’s comments during Flanders video was too direct. Her wording was way too specific in relation to episode itself.

She should have said something like - even though they get on my nerves I still care about my students...yes even Bart. I enjoy being their teacher.

I thought that was fine actually, it's been proven many times in both classic and modern episodes that Bart and Edna, while at times antagonistic, did have a lot of respect and love for one another (even if Bart bizarrely forgot about most of that here), it'd make sense for Edna to cite Bart as an example since by that point she lived right next to him and understood he wasn't a bad child at heart

but her comments in this part were so on-the-nose it came off convenient and unnatural imo. They made her say word for word what Bart wanted hear.

All she had to make clear is she actually enjoyed teaching and believed in her students. Maybe have Rod or Todd interrupt and ask even Bart Simpson? To give her a reason to compliment him.