in the latest nbminer, you don’t have to put any extra arguments… the lhr-mode is by default 1 and unlocks 75% of the full hashrate… your current hashrate is fine… your power consumption though is high… set pl to 120 and core between 1400 and 1500 which will limit max to 105W
p.s.: also set the fan between 65 to 75 to achieve better temps
p.p.s: for mem values, try between 2400 and 2600, in 50 increments, to find the best oc settings for your card