Really?
The effect can be easily achieved without a plugin by simply replacing the text "\n\n" with "\n", but the first prettify or running a plugin that saves the file together with prettify will ruin the whole effect.
Of course, you can change the
\src\Parsers\GumboInterface.cpp file in the Sigil code; to achieve the general effect, you only need to comment out two lines. To get more polished effects, you have to tinker with the code a lot.
I used this solution for a long time, but in the end I gave up and now I live with empty lines
