[DiapDealer]

As to why you're getting different output to the plugin runner window with what appears to be cosmetic-only changes: debug-printing to the plugin runner window is tricky at best. If your plugin is working as expected; trust that. Otherwise if you need to use extensive debug prints, it's almost always best to find a way to test your code outside of Sigil.

All output/results of a Sigil plugin are delivered back to Sigil's plugin window as an xml file. That xml file is then parsed and displayed via the plugin runner window. Depending on when, in the process, output with tags is printed, that output can actually get rendered by Qt instead displayed in its "raw" state.