Can we add mods/cc back in now that the Grim event has been fixed?

I wouldn't. The event isn't over yet, and week 2 has started a new round of bugs with things not going as planned. I've resorted to using a completely clean set of Sims 4 folders just for the events, and use it exclusively for events. (Was a suggestion last week) in hopes that this will prevent any possible conflicts with mods / CC.

When not playing the events, I just swap out the Sims 4 folder with my gameplay set of folders, and save it on my desktop until next week.