If you're intent on using agents, try having them work by themselves on one feature branch while you work normally on another. It feels like hiring a fast intern...

Highly opinionated: Regarding using agents for a main project or feature, as some do, I don't think there is such a thing as a "flow state." If you adhere to that working strategy, your hypothesis is that the agent is so much faster than you that you can get more done even without a flow state, even if the quality is a little worse, and your job has fundamentally changed from programmer to code reviewer. That will have its own set of skills for you to develop, such as efficiently reading their changes, managing costs and context, writing good prompts, etc.