Evidence Synthesis Methods Interest Group

Hi all:  We're working with a research group that ambitiously wants to wrap together 3 research questions in a single scoping review.  The questions all have a single subject (breast milk), but ask particular questions regarding 1. contaminants and rates of infection; 2. rates of infection of newborns through breast milk; and 3. adherence of mothers and caregivers to guidelines on preventing breast milk contamination. 

We're cautioning them that they really have 3 reviews here and might want to focus on just one--that said, we're pretty sure they'll want to proceed with all, regardless of #s involved.  If that's the case, does anyone know of guidance/rules regarding scoping reviews with these sort of related but separate questions about a single topic?  Most directly, I suppose, is whether they will need to register separate protocols for each one, or whether they can be combined in a single protocol?  This sort of multi-focused review is new to me, and I can't seem to find anything in Cochrane specifically about it. 

Thanks for any advice you all can share based on your knowledge and experience!  Jim