hanging indent conflict with section space

Question

In some parts of my document, I want to have hanging indent on paragraphs. I noticed that the section space gets messed up when I use \hangparas. Compared to other sections in the document, there is less vertical space between sections when I use the hanging package. How do I keep the same space between sections while using \hangparas ?

\documentclass[10pt,openany]{book}
\usepackage{fontspec}
\usepackage{libertine}
\usepackage{titlesec}
\usepackage{multicol}
\usepackage[autocompile]{gregoriotex}
\usepackage{fancyhdr}
\usepackage{verse}
\usepackage{enumitem}
\usepackage{longtable}
\usepackage{xurl}
\usepackage{hanging}
\usepackage[english]{babel}
\usepackage{blindtext}

\titleformat{\chapter}[display]{\normalfont\bfseries\centering}{}{0pt}{\Large}
\titleformat{\section}[display]{\normalfont\itshape\centering}{}{0pt}{}

\begin{document} 

\chapter{Some Chapter}
\fancyhead[CO,CE]{\textsc{Some Chapter}}

\section{Section w No Hanging}

\blindtext

\blindtext


\section{Section w Hanging}

\begin{hangparas}{1em}{1}
\blindtext

\blindtext
\end{hangparas}

\section{Next Section}
\blindtext

\end{document} 

Answer 1

The hangparas environment just after the section title doesn't reset \if@nobreak to false, because it changes \everypar before \@nobreakfalse is executed.

We can make it not ignore it.

\documentclass[10pt,openany]{book}
\usepackage{fontspec}
\usepackage{libertine}
\usepackage{titlesec}
\usepackage{multicol}
\usepackage[autocompile]{gregoriotex}
\usepackage{fancyhdr}
\usepackage{verse}
\usepackage{enumitem}
\usepackage{longtable}
\usepackage{xurl}
\usepackage{hanging}
\usepackage[english]{babel}
\usepackage{blindtext}

\titleformat{\chapter}[display]{\normalfont\bfseries\centering}{}{0pt}{\Large}
\titleformat{\section}[display]{\normalfont\itshape\centering}{}{0pt}{}

\makeatletter
\def\hangparas#1#2{%
  \setlength{\parindent}{\z@}%
  \everypar{%
    \if@nobreak
      \@nobreakfalse
      \clubpenalty \@M
    \else
      \clubpenalty \@clubpenalty
    \fi
    \everypar{\hangpara{#1}{#2}}%
    \hangpara{#1}{#2}%
  }%
}

%\def\endhangparas{\par\@nobreakfalse}
\makeatother

\begin{document}

\chapter{Some Chapter}
\fancyhead[CO,CE]{\textsc{Some Chapter}}

\section{Section w No Hanging}

\blindtext

\blindtext

\section{Section w Hanging}

\begin{hangparas}{1em}{1}
\blindtext

\blindtext
\end{hangparas}

\section{Next Section}
\blindtext

\end{document}