As the title says, the heavy handed mod doesn't work with the titan stasis melee, or even the new aspect from this season. For the original melee, I would assume it is because heavy handed works upon press, and the stasis melee uses half of the energy for the launch, and drains the other half on the swing, completely nullifying the heavy handed mod. As for the new aspect, I would think it is because it is refunding the melee ability active when you slide, which gets replaced when you stop sliding. I really want this to work into my melee build, since stasis is one of the cooler melees that I want to use this mod with for faster cooldowns.