I would recommend changing the hop schedule:
60 min 1 oz mosaic
10 min .5 oz mosaic
Flame out 1 oz mosaic and centennial
Dry hop:
3-4 days each even split mosiac/Centenial remove and add other half for 3-4 days
This will prevent grassy garlic from the mosaic. Also, need to get at min 4 oz...