This option right there can’t be found on the new UI. You can create the server, then from the server add the clients one by one instead of having them all open at once, saving TONS of time when debugging (it already takes some time to start a server, this makes it even more painful to use)
It starts the Server, but it doesn’t start the Clients and it doesn’t let you pick how many clients you want. It was already painful to test in a local server when everything automatically started, now having to manually start clients is even more painful