The current MCCC setting for Game Time Speed doesn't break anything that I've seen yet, I'm 3 generations into this save game since setting it with multiple played households. He's coded it so that alerts work properly for everything else, so I assume it would work for the actor career as well.
It even self-corrects the calendar now if you change it mid-game, though you do need to adjust any custom holidays and events already scheduled will get skewed for a few weeks (like starlight accolades won't be on sundays for a bit), but that also self corrects as soon as the ones that were already on the calendar clear out.
Just be advised that there are some mods which do not work if you change the Game Time Speed. Generally those mods warn you in their description.
