I like the physics in Konosuba's scene, but for more than just the booba bouncin though. In Dragon Maid's scene the blur lines make Kobayashi's slap seem like just a whiff and it comes straight down on Illulu's left boob, yet somehow both booba bounce. You just can't convince me that the energy of that whiff was angled towards both booba. On the other hand, Konosuba's just perfects those sorts details. Although it's a bit slower paced compared to Dragon Maid's you can watch Megumin wind back to properly give her slaps power, and Yunyun properly recoiled up and away in accordance. I have to say Dragon Maid's scene just can't compare in this regard
But on the other hand, Illulu's booba flailing takes up half the screen so I'm gonna have to declare this a tie.