An outline will always have a bit of difficulty with aspects or facets that cut across its usual boundaries. (Inheritance trees have the same problem, which is why we have mixins.)
Cross-cutting facets are often addressed by adding a column to the outline, one for each such facet, or by defining additional views. A “view” shows [a subset of] the data from a different perspective, perhaps with a different organization, suited to a different task.
I doubt that we have room for more columns in the Properties panel.
To handle alternate views, though, “Properties” could be tabbed, notebook-style. For example, a (hypothetical) “data bindings view” could be isolated in its own “data bindings” tab.