When I hit appr. 40 GB and realized that I did NOT use more than a small part of it anyway, I decided for a radical change. Now I have 3 main game folders. /The Sims 4 CAS with all the CAS stuff I download. /The Sims 4 BUYBUILD for BUYBUILD downloads. I load any of those up to a)create sims, pick out good new stuff that I really like and will use b)build/refurnish houses or create rooms with good new stuff
Then I save the sims/households or lots to library, and use the Sim Tray Importer to export the sims/lots WITH the new CC. Then I load up my /The Sims 4 MAIN and import the stuff. This way I can both be a totally addicted downloader and have access to it all when I want, and at the same time have a clean, lean game which has acceptable loading times and not much lag. And I can find stuff in CAS and BUYBUILD mode, when needed.
Only a few carefully picked creators is added in complete form for the game. I will also merge, when I get a little bit further in the picking out-process. Nowadays, when you can unmerge at any moment and change the merged files easily (regroup, delete, add) it's a piece of cake.