100/10 for mobile usability. Panning, Zooming, selecting and moving was so seamless I thought I was tripping out.
Author is top notch in my book. I'm a sucker for someone taking a complex problem and distilling out a simple solution. I don't know of higher praise to give a developer.
const $ = (id) => document.getElementById(id);
Yeah, my first thought was that the diagramming bit needs to be ripped out into its own library, because I can see a use for the diagramming bits for more than ER diagrams.