Thinking of all the apps WT provides, if that's what they are (apps) for looking at relationships and connections and looking at paper trails and looking at DNA comparisons and ... the relationship is still uncertain?
So what is lacking is a document or two where they are stated to be siblings.
Not sure being able to put both of their WT ID# on the same form (like what I am writing on) at the same one time would be helpful, excepting it provoked someone one to hold up the documentation and yell "Here, I have it here!!"
Myself, I would just drag and drop their profile URL, both of them, onto the form (used to ask a question) ...
Well, I don't know, but I suppose if WikiTree Tech looks at the idea, and likes it, they'll add it to the list of improvements -- I think they tend to work first on the apps or improvements that have "a lot of popular demand"