I remember one time in quick play I hit a nair->forward tilt after a parry from baiting Yoshi from his down b. The only difference is that it couldn't have been hit box 2, it was in the later frames of the nair it seems like.
Yeah nair always combos. At starting percents you want the hitbox that sends far away but at higher percents you want this hitbox for kill confirms. This into bair is just bonkers
At starting percents a forward air into grab does fine imo. Nair starts REALLY cooking around 60% like right right here. You just have so many kc options depending on how you land the Nair