Well, it's tricky because Reader inserts walk a fine line. Stanley's a conman with a surface charm, but the depth is in his contradictions – the selfishness that bleeds into protectiveness for Ford and Soos and the kids. A good fic for him has to let the Reader be flawed too, someone who sees past the 'Mr. Mystery' act but doesn't magically fix him. Maybe they call him on his bullshit, or get reluctantly dragged into a scheme, and that friction is where you see his real gears turn. It's not about romance saving him; it's about another person becoming part of the Gravity Falls weirdness he's tangled in, forcing different shades of his personality to surface. I read one once where the Reader was a rival grifter, and the dynamic was all about one-upmanship that slowly morphed into a wary, genuine respect. That felt true to character in a way fluffier stuff doesn't.
A shallow connection happens if the Reader is just a mirror reflecting back admiration. The deeper pull comes from creating a new pressure point in his life. How does Stanley, who's built walls to survive, react when someone sticks around not because of a con, but in spite of it? That exploration can reveal his capacity for loyalty and his deep-seated fear of being a disappointment, which are his core wounds. The connection feels earned when the Reader's presence illuminates something we already sensed about him from the show, but from a fresh, intimate angle.