I was doing about the same until last year. I upped it 3oz per gallon in the backpack. By the end of the season, it’s wearing off of some spots but I usually don’t hit it again.
If you're spraying with a backpack and wand , you're prolly putting out way too much at 1% . Folks tend mix it too hot and spray stuff till its running off the leaves.
I have a wand with a dual nozzle, a pretty fine mist and I’m moving on pretty quickly. Certainly not claiming to be an expert but I’ve been around it for a very long time. It’s too expensive to waste. I agree that a lot of folks probably apply way more than necessary.
