Either slightly below or above him, his entire kit is useless. Rocketpunch? You either stop in your tracks or fly over your targer.
Uppercut? Mostly misses, but even if you hit, the target will be placed in an advantageous position.
Slam? Well tough luck, the slam just does not connect.
This is due to Doomfists kit being entirely based on horizontal movement. The uppercut even is there to have the target fly away from him.
Can’t this be addressed?
If you don’t jump before rocket punch goes off, you’ll hug the ground. The only big issue is upward inclines preventing you from using the jump-cancel boost.
Uppercut still has some issues with verticality, but it’s mostly due to slanted ceilings flinging DF and his target in awkward directions.
Slam is a bit odd. As long as your model doesn’t hit a ledge, you should be fine. Slam is a bit odd displaying the reticle over ledges, as you don’t clip through every obstacle to get to the reticle.
Regardless, I think it’s fine to have DF’s verticality to be weak, as he already is the king of horizontal mobility.