So, I was going into this expecting to hate on it, but surprisingly, I rather enjoyed the episode.
The Lisa B Plot was probably the main highlight of the episode for me, the Octopus was adorable, and Lisa did have some badasss moments in kicking the shark to defend the Ocotpus (which is interesting, given her focus on animal rights, that she would kick a predatory animal to save another animal that is said predator's prey). Thinking about it, Lisa kicking the shark is interesting as it shows that while Lisa is a massive animal rights activist, she does have her moments of weakness in those rights, showing that 1. She isn't a Mary Sue and 2. She isn't a PETA Preacher. Also, the "Future Nature Documentarians" club is interesting, and its nice to see that it isn't filled with just the smart kids, as Lewis's look-alike (who I headcanon to be Lewis's brother, Henry Clark) and Janey Powell part of that group too.
As for the main plot itself, which I was expecting to hate, I rather enjoyed it. The whole "has a crush on a teacher" stuff was rather minor imo. The only time I really noticed it is when Peyton's husband Darryl arrives and Bart takes out the Water Fountain in rage. I will say, it is that moment that makes me rate the episode a 9 and not a 10. Aside from that, its nice to see that Nelson & Milhouse care for Bart's wellbeing.
Also, there's some interesting lore in this episode, mainly:
1. Miss Hoover has taught Bart before when the latter was in 2nd Grade
2. Springfield Elementary School has 6 Grades (which was stated before in "Mathlete's Feat" iirc).
Anyway, like I've already said, I give this episode a 9/10: Enjoyable, with the main flaw been the Water Fountain scene.
Update: Almost forgot so state my opinion on Ms. Peyton. I like her, and I do hope we see more of her, I remember seeing someone complain about her been a Mary Sue, and honestely, I can see where that person came from. I don't see her as a Mary Sue thou, but as I said, I do hope we see more of her so her character can be built more. I will always prefer Ms. Edna Krabappel thou, not sure about you guys, but I don't think anyone will ever replace her legacy on the series.