git worktrees are the canonical solution

worktrees are good but they solve a different problem. Question is, if you have a lot of agent config specific to your work on a project where do you put it? I'm coming around to the idea that checked in causes enough problems it's worth the pain to put it somewhere else.

worktrees are a bunch of extra effort. if your code's well segregated, and you have the right config, you can run multiple agents in the same copy of the repo at the same time, so long as they're working on sufficiently different tasks.