Too much body filler?

Hi! Im considering getting a liquid BBL w/ Genefill. I've already had a regular BBL but recently lost some weight. BBL results were good & natural looking but now that I've lost weight it feels like my butt looks really deflated. I know the place Im considering has really wonderful results & I know that HA filler isn't a long term result & cost is higher, however I don't have enough fat to undergo another BBL. Are there any long term safety issues w getting 200-400 ml of HA filler in butt/hips?