Easy: each worktree starts services on new ports. https://termic.dev goves you ENV variables for this, oir you definee your own custom named variables, and termic assigns ports for each wotktree.
Or if the stack is too complex to start it in parallel, use spotlight to sync changes to main checkout from a single worktree at a time. You can only test one at a time, let's be serios. https://termic.dev/docs/spotlight/