This is where my intersection/roundabout idea comes in. As long as the roads leading to a particular place are long enough, the required world could be loaded in while the other one is offloaded.
This one was done for the Climb Portal, but I’ve done one in the past for “worlds”.
Honestly though, I’d settle for a small loading blip the same way we have when moving to a different event world. I don’t see why it would necessarily have to result in a new activity, either.