Peter,
I ran into the issue I have with Layout legends again this morning. The issue is with image rendering in JPG/GIF/PNG. It works fine in PDF rendering. I'm attaching a sample of what I see on screen, PDF output, and JPG output. As you can see, the JPG output is different than the rest with the legend items being shrunk relative to the map object. Style 5 is supposed to match the map object in the lower left. It does for PDF and on the screen, but not in the JPG.
This is what I see on screen.
Here is the PDF output, it looks good.
And here is the JPG output, where the styles in the legend are shrunk. I've played with all the rendering options and I can't find anything that fixes this effect. This effect also happens with line and polygon objects, but its less relevant for polygons. Lines and point styles are the issue. It looks like the legend text might be shrunk too relative to PDF rendering.