I get plenty of vertical kills in Build 2, albeit most are at ~150%. IMO Moon Launcher is essential to balancing out Heavy Gravity's quirks, it allows for aerial followups because the x1.37 Upward knockback allows for just the right amount of hitstun, while also giving players plenty of oppurtunities to tech out of combos.
Vanilla Aerials ~ Send opponents forward and up, plenty of knockback so a high chance of Airdodge and no followup (cept Hoo Hah)
Regular SL Aerials ~ Still send opponents forward and up, but with less landing lag followups are much more possible.
SLHG Aerials ~ Send opponents forward and down, if they hit the stage they are forced to tech. If they miss the tech, you get a nice juicy F-smash on them as they get up. If an opponent is knocked off stage they are sent sideways and downward, and with recoveries being nerfed in HG, most would consider the offstage to be both intimidating, as well as an area for styling on someone.