I don't know that is impressive to me. I wish I had shoulders like that.
What is your bench and squat routine? Adding board presses to your bench routine may help. But if I were looking for big gains I would be working more closely to your 1 rep max. I would add a light work day as well and use bands on the bar.
Squats are well dam near the hardest to make big moves on or at least for me. But I would work sets around my 1 rep max and adding a light day of sets to failure.
