I use a workflow that has different named subagents. [1] Agent profiles can be pinned to models. So you set the model you want on your main thread as the orchestrator. Create an agent for the "planner", "implementer", and "reviewer" and set the model you want for each. Right now I am orchestrating and implementing with Deepseek, planning with Astra, and reviewing with Opus.
I am doing this with the Pi harness right now. To use a Claude monthly plan you need to use the pi-claude-bridge plugin.
If you are using just Claude for example you can use Sonnet as the implementer and Fable/Opus as the planner.