So this didn't go very well.
On my list of episodes to give a second chance, I skipped "Filli Vanilli" and "Twilight Time" due to my opinions on them not changing much. This lead me to "It Ain't Easy Being Breezies", the episode directly after "Twilight Time". Unfortunately, this episode is still not a favourite.
The episode starts off by aggressively promoting the Breezies as cute. Your mileage may vary on if they actually are or not, but the lines in the first few parts of the episode push it far too hard. The episode really doesn't change this focus, desperately hoping that the cuteness of the Breezies is enough to carry the episode. No matter how cute the Breezies may be, this simply isn't a strong enough foundation for the episode, and it's not supported by jokes or much in the way of otherwise interesting moments. Sure, later on there's the incident with the bees, but even that is propped up by "cuteness", which in actuality does work a bit better due to it being focused more on Fluttershy. At the same time, it's just not enough to drive the episode.
What makes the episode ultimately work, even if just barely, is how Fluttershy is characterized. She undergoes actual character development, which is a bit different from the other key episodes where previous character development is merely reinforced. Fluttershy had already known how to say "no" at this point, but here she learns that sometimes it's best to say "no" for other people's good and not just her own. It's a fairly strong bit of character development, and the real backbone on the episode.
Honestly, this episode doesn't really inspire me to say much. Maybe some people who do enjoy the Breezies may like it more, but it doesn't really work for me on that level. It boasts strong character development at its core, but the ultimate tone of the thing just isn't for me. For a key episode, though, it's far from the strongest.