Yeah would be nice. I want them for the same reason :D Too many sims are hard to handle and it's nice to send them away for a while and when they get back they have nice moodlets or bring something along with them. Talking about the mod.
It's especially nice for kids. As they do have a bit limited gameplay right now.
edit: as for the problem in this thread... many sims are fine if they all have an activity but not all of them always have something to do. Especially as in my gameplay, legacy, I only ever really concentrate on my heir/heiress but I do keep some siblings around for stpry purposes cause I don't wanna move everyone out when they're just a baby. I'm not trying to run a baby making machine kinda game :D I want it to make sense. But don't always have the interest in spares.