I tested with Billy's Bashdown ability (at rank 3 so it's considered heavy melee), and the following items were not applying any bonus weapon damage on hit
I get similar results with others heroes dealing melee damage abilities (Bebop, Calico, Drifter, Viscous)
- Close Quarter
- Point blank (the slow effect is applied)
- Opening rounds
- Melee charge (The cooldown is triggered but no extra damage)
- Crushing Fists (The cooldown is triggered but no extra damage, Still apply 2 stacks)
I get similar results with others heroes dealing melee damage abilities (Bebop, Calico, Drifter, Viscous)