Multiple working directories from one repository — the standard isolation pattern for parallel agents.
git-scm.com/docs/git-worktree ↗Run three or four agents against the same repo without them stomping each other's changes. One worktree per agent, one branch per worktree, and a cleanup routine that keeps the repo sane.
Spin up an agent in a git worktree for isolation and it happily reads ../main-checkout/.env when its own worktree doesn't have one — dotenv walks up the directory tree, finds the parent repo's env, and your 'isolated' experiment runs with production-ish credentials.
Four parallel agents sounds like a 4x multiplier until they meet in the same file. Worktrees, task routing, merge order — what's your actual topology?