I break polygons.
Yes, I know, I'm posting a ton. I just wanted to point out that Quixel will create a PSD for each map for each mesh group. Here's a list of mine with the above modified G3F open. This is why I advise to narrow down your mesh groups to the uv maps and use color ids. Ideally, for things like game assets, props, most clothing, you'd only have about 4 PSDs since everything would be laid out over a single non-overlapping UV map.