I’m planning on temporarily moving more than 8 sims onto a lot for storytelling purposes using MCCC, and I want to create a separate copy of my save just in case I mess something up. I seem to remembe...
I believe the devs have said it's actually good to use 'save as' once in a while because in some small ways it helps to refresh a save from corruption and glitches. I tend to play the same saved games for years so I do a 'save as' once in a while and continue with the new file and eventually delete the old ones. But like people have said above, just make sure you name or number your saves in a way that helps you distinguish between them.