Headers and line counting in reledmac/reledpar

Question

I am converting an old FrameMaker file to XeLaTeX. As it deals with text editions of ancient documents, multiple readings, and the like, it seems to make sense to use reledmac/reledpar. However, being new at this, I am not sure I am going about it in the best possible fashion.

Please consider the following MWE below showcasing an original text in Sumerian and Akkadian with a translation into English. I've run into a few issues.

1. The headers "Obverse...", "Reverse", etc. only need to be given once; I do not need separate headers for left and right columns.
2. They can be quite long, i.e. longer than the width of the left column. Thus I found the use of \pstart[\subsubsection{Obverse...}] problematic.
3. So I tried to use regular memoir header commands outside the edition with column pairs in between. This looked nice but I was not able to figure out how to continue the numbering of each column after a header, as seen in the output from this MWE.
4. Thus I resorted to simulating the headers as single-column text, suppressing the line counting mechanism. This worked quite well as you can see.
5. In some instances, however, I do wish to restart the numbering after a simulated header. This is quite easy by getting rid of the \pausenumbering and \resumenumbering in favour of \beginnumbering and \endnumbering. Unfortunately, as a side-effect, the right-hand column is then not numbered continuously, which it always should be regardless.

So the first two questions are: is this the right way to handle my needs, and is it possible to keep continuous numbering in the right column, regardless of whether the left column restarts?

The other thing to note is that the practice in my field is to number each line of text as it appears on the original document. The romanized equivalents, however, can typeset in multiple lines (see the first line of the obverse). In order to avoid numbering part lines, I have entered manual \skipnumbering commands as necessary, but this strikes me as potentially error prone if, say, the document font size changes and the line breaks therefore change.

I am wondering whether this is indeed the thing to do.

I have considered the various examples provided in the documentation but given my needs I'm a bit stumped and any pointers would be appreciated.

% !TEX TS-program = xelatexmk
 \documentclass[%
    a4paper,            % minus margins = A5
    11pt,               % reduce to 10 if required
    twoside,            % two-sided printing
    one column,         % single column of text on a page
    openright,          % chapters/lessons begin on odd pages only; review later
    ]{memoir}

% GENERAL PAGE LAYOUT (in the order suggested by memoir)
\setulmarginsandblock{67mm}{60mm}{*}    % #1 is upper, #2 is lower, #3 is ratio
\setlrmarginsandblock{50mm}{50mm}{*}    % #1 is spine, #2 is edge, #3 is ratio
%\setheadfoot{⟨headheight⟩}{⟨footskip⟩}
\setheaderspaces{*}{10mm}{*}            % #1 is the head drop, #2 is the head separation, #3 is ratio
%\setmarginnotes{<separation>}{<width>}{<push>}
\settypeoutlayoutunit{mm}               % default is pt
\checkandfixthelayout
%\raggedbottom                          % turn this option on *if* there are too many problems

\nouppercaseheads

\usepackage{libertine}
\usepackage{polyglossia}
    \setdefaultlanguage[variant=british]{english}
    \setotherlanguage[]{french}
    \setotherlanguage[spelling=old]{german}

\usepackage{reledmac}
\usepackage[nosyncpstarts]{reledpar} 
    \Xarrangement[A]{paragraph}
    \firstlinenum{1}
    \linenumincrement{1}
    \setlength{\linenumsep}{0.5em}
    \sublinenumberstyle{alph}
    \setlength{\Lcolwidth}{0.49\textwidth}
    \setlength{\Rcolwidth}{0.49\textwidth}
\newcommand{\aw}{Aw~} 
\newcommand{\akk}[1]{{\sffamily\textit{#1}}}
\newcommand{\smn}[1]{{\sffamily\addfontfeature{LetterSpace=10.0}#1}}
\newcommand{\D}{{\sffamily\textsuperscript{d}}}
\newcommand{\dtm}[1]{{\sffamily\textsuperscript{#1}}}


\begin{document}
\chapter{Text Editions}
\setsubsecheadstyle{\sffamily\large\bfseries\centering}
\counterwithout{subsection}{section}
\newcommand{\presection}{}
\newcommand{\presubsection}{\aw}
\newcommand{\presubsubsection}{}
\setsecnumformat{\csname pre#1\endcsname\csname the#1\endcsname\quad}
\addtocontents{toc}{\protect\renewcommand{\protect\cftsubsectionpresnum}{\textsc{aw}~}}

\subsection{OBJECT}
Here is a multiline description of the object. Here is a multiline description of the object. Here is a multiline description of the object. Here is a multiline description of the object. 

% Simulated subsubsection header "Obverse"
\vskip 3.25ex plus 1ex minus .2ex
\beginnumbering
\sffamily\large\bfseries\raggedright\pstart\noindent\skipnumbering Obverse (numbered as in YOS~5)\pend
\endnumbering
\vskip 1.5ex plus .2ex
% Obverse in two columns
\begin{pairs}
\begin{Leftside} 
\beginnumbering
\pstart
\noindent\smn{[gud]-giš} \smn{[gud]-giš} \smn{[gud]-giš} \skipnumbering\smn{[gud]-giš} \smn{[gud]-giš} \par
\noindent\smn{a-ru-a} \akk{nu-úr}–\D\smn{utu}
\pend
\pstart
\noindent\smn{1 gu₄ mu 3(1)}\par
\noindent\akk{a-bu--wa-qar}
\pend
\pstart
\skipnumbering‹space›
\pend
\pstart
\noindent\smn{ì-dab₅} \akk{i-ba-aš-ši}--\smn{dingir}
\pend
\pausenumbering
\end{Leftside}
\begin{Rightside} 
\beginnumbering
\pstart
\noindent\textsubscript{1–2~}(re:) 1 draught ox, votive offering of Nūr–Šamaš (and)
\pend
\pstart
\noindent\textsubscript{3--4~}1 three-year old ox, (votive offering of) Abu--waqar
\pend
\pstart
\skipnumbering
\pend
\pstart
\noindent\textsubscript{5~}Ibašši–{dingir} has taken (them).
\pend
\pausenumbering
\end{Rightside}
\end{pairs}
\Columns
% Simulated subsubsection header "Obverse"
\vskip 3.25ex plus 1ex minus .2ex
\resumenumbering
\sffamily\large\bfseries\raggedright\pstart\noindent\skipnumbering Reverse\pend
\pausenumbering
\vskip 1.5ex plus .2ex
% Obverse in two columns
\begin{pairs}
\begin{Leftside} 
\resumenumbering
\pstart
\noindent\smn{[gud]-giš}\par
\noindent\smn{a-ru-a} \akk{nu-úr}–\D\smn{utu}
\pend
\pstart
\noindent\smn{1 gu₄ mu 3(1)}\par
\noindent\akk{a-bu--wa-qar}
\pend
\pstart
\skipnumbering‹space›
\pend
\pstart
\noindent\smn{ì-dab₅} \akk{i-ba-aš-ši}--\smn{dingir}
\pend
\endnumbering
\end{Leftside}
\begin{Rightside} 
\resumenumbering
\pstart
\noindent\textsubscript{1–2~}(re:) 1 draught ox, votive offering of Nūr–Šamaš (and)
\pend
\pstart
\noindent\textsubscript{3--4~}1 three-year old ox, (votive offering of) Abu--waqar
\pend
\pstart
\skipnumbering
\pend
\pstart
\noindent\textsubscript{5~}Ibašši–{dingir} has taken (them).
\pend
\endnumbering
\end{Rightside}
\end{pairs}
\Columns

\end{document}