Classic Mochi Au Lait WACKY AF chapter. I did not miss this.
This chapter was actually pretty cool up to that last scene. Like, it added to the world building while confirming that the effects of the potion DO wear off over time. So the theory that it's more of an attraction booster instead of a do-it-all love-curse potion checks out!
which also explains why, while characters changed after drinking the potion, most of them didn't pursue a romantic relationship with Itsumi. And for the ones that did, it's not like they suddenly do whatever Itsumi wants. They kept their individuality.
So, the love potion is just a plot device. A vehicle to learn more about the wacky cast. But at some point, it isn't even needed anymore.