I gave one model the same 44-node architecture twice.
The first time I asked for raw SVG — place every box, route every edge, hand me the coordinates. The second time I asked it to describe the same system as typed JSON and let a layout engine draw it. Same model, same session, same brief. The only thing I changed was the output boundary.
The boxes are fine in both. I want to be upfront about that, because the usual version of this pitch is out of date. Models place labeled boxes well now. If you ask a current frontier model for a six-box flowchart as SVG you get a clean six-box flowchart, and if that's what you need, go do that — it's the right tool and I'm not going to pretend otherwise.
What broke was the edges.
With no routing algorithm the model just drew long diagonals straight through unrelated boxes. Not a few — everywhere the graph got dense. And when I changed one node, the entire hand-placed coordinate layout had to be regenerated, and came back different.
