I have a couple of Lume Cubes on mine which weigh 300 grams total with brackets. The flight time is cut in half to maybe 14 minutes from their weight on mine. How much damage is being done I don't know, but it may get replaced soon for a 20MP camera drone (P4 Pro, Inspire 2, or whatever.) so if it goes gets smoked from being overloaded with the Cubes I really won't care. Likely some extra heat is being cooked up in the motor or ESC circuitry as it does take some extra umph! at times.
Someone had posted a video with water bottles attached to theirs. Someone better with search might know of it.