Depends on your intent.  Currently, I only have the K4 Base installed on my system but haven't had a need to use them just yet.  Installing them into their own runtime won't be a bad idea, it centralizes all your content into one location.  That would be my approach.  IIRC, there is a toddler package in that bundle.  Don't bother to install that one.  It was exclusively created for DAZStudio and does not play well with Poser at all.  I picked that one up as a freebie when K4 came out.  It is just in archive right now.