Should I try to do most of my miles at higher HR?
At, AeT = 160 and AnT = 174, (AnT-AeT) is less than 10% of AnT. Based on this, you are not Aerobically Deficient.
From this article –
If the difference is 10 percent or less of the AnT heart rate, then you will need to reduce the amount of Z2 training and substitute more Z1 for your aerobic base training or you will run the risk of overtraining by running too fast (Z2) too much of the time.