Ok I've run a bunch of different tests, and this is on both modded and never modded saves. If you run into the loading screen issue you MUST clear cache to access your affected world in another save (this is for the people who said they experienced it on new saves). In my case ALL of my San MyShuno lots are modified, one is a pool, one is a restaurant, and one I replaced Stargazer with a residential rental. I only have one save with Stargazer replaced with a residential rental and it is the ONLY save I cannot load into San MyShuno. So it does not seem that, atleast, other lot types are impacting it. It's specific to the combination of residential rental and penthouses.
Lastly, the workaround does not work for me. There is no option that allows me to travel to the lot without a loading screen, which means the white screen. I even tried going to the gym and having my Sim go to the lot since it's across from it, but that did not work. So right now San MyShuno in my main save is completely not playable.
There will always be a loading screen. Did you read the instructions carefully? The goal is to get into the world without using the world selection screen. And you do that by starting a social event from a working world, and choosing a lot from the affected neighborhood as the destination.
* But do not try it from a session where you've already received the white screen. You have to exit the game and start fresh.
