bibunit resets appendix number

Question

I have a document that is split into two titles. The main document contains section 1 and appendix A, and the supplement contains appendix B (the rest of the appendices).

The numbering is fine without bibunit, but it resets with it. How to prevent the reset?

Maybe start with a manual hack that starts the supplement appendix from a specific letter?

\documentclass[acmtog]{acmart}

\usepackage{blindtext}
\usepackage{bibunits}

\acmJournal{CIE}\acmVolume{0}\acmNumber{0}\acmArticle{0}\acmYear{202x}\acmMonth{0}

\let\maketitlesup\maketitle
\usepackage{xpatch}
\xpatchcmd{\maketitlesup}{\@mkteasers}{}{}{}
\xpatchcmd{\maketitlesup}{\@mkabstract}{}{}{}

\begin{document}
    \title{Title}
    \author{Author}
    
    \maketitle
    
    \begin{bibunit}
    
    \section{1}
    \blindtext
    
    \appendix
    
    \section{A}
    \blindtext
    
    \end{bibunit}
    
    \setcounter{page}{1}
    \title{Title---Supplement}
    \maketitlesup
    
    %\appendix
    
    \begin{bibunit}
    
    \section{B}
    \blindtext
    
    \end{bibunit}
    
\end{document}

Answer 1

Acmart finally supports biblatex. It has, however, a similar issue, but at least I can set the counter manually.

\documentclass[acmtog,natbib=false]{acmart}

\usepackage{blindtext}

\usepackage[datamodel=acmdatamodel,style=acmauthoryear]{biblatex}
\addbibresource{/prj/notes/paper.bib}
\addbibresource{/prj/notes/levi.bib}

\acmJournal{CIE}\acmVolume{0}\acmNumber{0}\acmArticle{0}\acmYear{202x}\acmMonth{0}

\let\maketitlesup\maketitle
\usepackage{xpatch}
\xpatchcmd{\maketitlesup}{\@mkteasers}{}{}{}
\xpatchcmd{\maketitlesup}{\@mkabstract}{}{}{}

\begin{document}
    \title{Title}
    \author{Author}
    
    \maketitle
    
    \begin{refsection}
    
    \section{1}
    \blindtext
    
    \appendix
    
    \section{A}
    \blindtext
    
    \cite{myles14fieldtrace}
    
    \printbibliography
    \end{refsection}
    
    \setcounter{page}{1}
    \title{Title---Supplement}
    \maketitlesup
    
    \begin{refsection}
    \appendix
    \setcounter{section}{1}
    
    \section{B}
    \blindtext
    
    \citet{shtengel17}
    
    \printbibliography
    \end{refsection}
    
\end{document}