Ah - xhigh is probably what you want. Their docs suggest xhigh for agentic coding, though judging by their blog high should be better than 4.6 max (ymmv)

I've always used high, so maybe I should be using xhigh

I'm actually in the process of switching all of my agents to sonnet, and going to try to drop down to medium.

I used up 1/3rd of my context in less than a day. I am working diligently to do whatever I can to lower token usage.