Cyclical dependency issues still in 4.9

Question is, isn’t that too many childs and references?
And what exactly is a reference, issue coming from, casting?
Because when im checking my spell system actor, which handle everything, from animations to widgets it has references everything to interface and than to actual blueprints and only two widgets which has casting, reference blueprint to blueprint.
Mb that’s an idea, for hardly dependent stuff, to use interfaces?
I’m not criticizing, i’m asking.