At.. 2.5 GCD, Malefic 3 is 220/2.5 = 88 potency/s, animation lock I think is around.. 0.75 (I believe latency might affect the total animation lock though, double weaving the draw + something else feels pretty bad)
If you just clip your dot and cut the Malefic, over the course of 2 mins (where you could end up weaving 13 times in full offense, partly due to Redraw, and 3 EDs used), ends up with only needing at least 102.5 potency (at 0ms delay, value only drops from there, down to 94.11 at 80ms) on Stella to make it worth it. (150 potency is around a 3% dps increase or so, 137 is a 2% increase or so, 170 potency is a 4.44% increase or so)