Often we want to reference multiple views in a single callout, for example with snow melt systems. Currently there's no good way to do so, we have to resort to a plan note directing contractors to the details.
While I'm at it, the ability to add a sub-category to the callout would be handy as well - for things like conduit trenches or ductbanks we use a single detail with a,b,c,etc. callouts within the detail to describe each case.