You can do what I do.
I created a "template save".
I went through the annoying task of creating a sim, just a random one that I deleted, but I put them on an empty lot and saved the game as "SAVE TEMPLATE".
Then whenever I want to just go in and mess around in the world, check out a new world, look at all of the new BB content from new DLC, test a piece of CC I created or whatever it may be, I use load that save and I'm not forced to go into CAS that way.
If I end up actually playing the game, I then do a "Save As" and rename it something else, so my "template save" is always preserved.
