Different style for appendix section heading via KOMA-script

Question

I like the use of hanging section numbers in the margin. But when I move to the Appendices, I would like to revert the behavior back to normal.

Additionally, I'd like to start the name of the appendix on a new line (but not in the ToC), for example:

Appendix A

Something appended

Below is a MWE with the issue, but cref and everything EXCEPT the hanging Appendix X issue and it is lacking a line break between Appendix X and the name of the appendix:

\documentclass[12pt,
twoside=false,
letterpaper,
hidelinks,
parskip=half+,
%onehalfspacing,  % see setstrecj after \begin{document}
bibliography=numbered,
numbers=noenddot]{scrartcl}

\renewcommand\sectionlinesformat[4]{% used by free-standing headings with style=section
    \makebox[0pt][r]{#3}#4}

%\usepackage{appendix} % use this if you want Appendix in the TOC
\usepackage[titletoc,title]{appendix} % use this if you want Appendix in the TOC
\usepackage{hyperref}
\usepackage[nameinlink,noabbrev,capitalize]{cleveref}  % cref

\crefname{appsec}{Appendix}{Appendices}


\begin{document}

\tableofcontents

\section{Some section with number in the margin}
Reference to \cref{appb}


\begin{appendices} 
\crefalias{section}{appsec}  % 

\section{Something appended} \label{appa}

And here is a MWE example of my hacky workaround. This is how I want things to appear, but I lose the ability to use cref, and if I want to add subsections the numbering falls apart:

\documentclass[12pt,
twoside=false,
letterpaper,
hidelinks,
parskip=half+,
%onehalfspacing,  % see setstrecj after \begin{document}
bibliography=numbered,
numbers=noenddot]{scrartcl}

\renewcommand\sectionlinesformat[4]{% used by free-standing headings with style=section
    \makebox[0pt][r]{#3}#4}

%\usepackage{appendix} % use this if you want Appendix in the TOC
\usepackage[titletoc,title]{appendix} % use this if you want Appendix in the TOC

\usepackage{hyperref}
\usepackage[nameinlink,noabbrev,capitalize]{cleveref}  % cref

\crefname{appsec}{Appendix}{Appendices}


\begin{document}

\tableofcontents

\section{Some section with number in the margin}
Reference to \hyperref[appb]{Appendix B}


\section*{Appendix A\\Something appended} \label{appa}
\addcontentsline{toc}{section}{Appendix A Something appended}   

\section*{Appendix A\\Another thing appended} \label{appb}
\addcontentsline{toc}{section}{Appendix B Something appended}   


\end{document}  

Answer 1

Here is a suggestion without package appendix:

\documentclass[12pt,
  %twoside=false,% default
  letterpaper,
  hidelinks,
  parskip=half+,
  bibliography=numbered,
  numbers=noenddot
]{scrartcl}
\usepackage{lipsum}

\renewcommand\sectionlinesformat[4]{% used by free-standing headings with style=section
    \makebox[0pt][r]{#3}#4}

\providecommand*\appendixname{Appendix}
\newcommand*\originalappendix{}
\let\originalappendix\appendix

\renewcommand\appendix{%
  \originalappendix
  \renewcommand\sectionformat{\appendixname~\thesection\autodot}
  \renewcommand\sectionlinesformat[4]{%
    \ifstr{##1}{section}
      {##3\\*##4}% sections
      {\makebox[0pt][r]{##3}{##4}}% subsections etc.
  }%
  \renewcommand\addsectiontocentry[2]{%
    \addtocentrydefault{appendixsection}{##1}{##2}%
  }%
}

\DeclareTOCStyleEntry[
  level=\sectiontocdepth,
  indent=0pt,
  numwidth=1em,
  dynnumwidth,
  numsep=1em,
  entrynumberformat=\entrywithprefix{\appendixname}
]{section}{appendixsection}

\newcommand\entrywithprefix[2]{#1~#2}

\usepackage{hyperref}
\usepackage[nameinlink,noabbrev,capitalize]{cleveref}  % cref

\begin{document}
\tableofcontents
\section{Some section with number in the margin}
Reference to \cref{appb}
\appendix
\section{Something appended} \label{appa}
\lipsum[2]
\section{Another thing appended} \label{appb}
\lipsum[2]
\subsection{Subsection in appendix}
\lipsum[3]
\end{document}

Run three times to get

Answer 2

I found a solution that might be considered inelegant, but it works for me, and I can use the structure of the first code block shown in the question (where I can take advantages of the appendices packages and use the titletoc and title keys).

I simply looked at the KOMA-Script manual, found the default definition of \sectionlinesformat, and re-stated immediately (omitting the \@hangfrom) after beginning the appendices, and added a line break as follows.

\begin{appendices} 
\renewcommand{\sectionlinesformat}[4]{%
    \hskip #2#3\\#4%
}
\section{Something appended} \label{appa}
\end{appendices} 

I imagine it's better practice automatically include this command when beginning the appendices environment, perhaps xpatch is the way to go.