"It's more convenient at the time when we can just attach new worlds to Downside, but having been attached to Downside before we came along is only dubiously advantageous. The question is whether you have a nice afterlife, and if Downside was dubious the other ones we've found are mysterious or worse. We'll check it out - assuming you don't mind our leaving a node in the world that will sync up its progression of time and allow us to come and go without waiting for Milliways doors."