a level 20 lightning golem gives 9% attack/cast speed buff and the quality on anomalous increases the buff effect by 1% per qual.
at level 20 there should be a break-point at 11 or 12% qual, but PoB doesn't give anything for quality from level 1 to 20.
interestingly, at gem level 21 (the golem buff goes to 10%) there are break-points at 10% and 20% quality like you'd expect
a level 20 lightning golem gives 9% attack/cast speed buff and the quality on anomalous increases the buff effect by 1% per qual. at level 20 there should be a break-point at 11 or 12% qual, but PoB doesn't give anything for quality from level 1 to 20.
interestingly, at gem level 21 (the golem buff goes to 10%) there are break-points at 10% and 20% quality like you'd expect