Bellerophon

I understand that Paint.NET isn't a command line editing tool, and that commands to actually edit or modify the content of images won't be available. But does anyone know if a converter or command exists that would allow me to render out .pdn files to .png in a batch file? I'm working with a large number of assets that I'd like to have an automated pipeline to process them into a form usable in a project, and I'd like to keep them in nice layered .pdn files and just be able to double click a bat to render those to .png versions and then process them into the form my project needs via an imagemagick script.

I'm working on some plans right now using Paint.NET, and I often want to draw lines a certain distance or with a gap from another. It's easy when a line is narrow, but when it's, say, twenty pixels thick, it's hard to tell just how it's going to line up with other elements of the picture. Given that radius is relevant, maybe when we have the line tool selected and the line is more than a few pixels thick, we should see the same radius circle around the cursor as we do with the paintbrush tool, so we can see how thick the line will be in-image.