reset section numbers at \part

(this is not a bug but a feature request)

As reaction to https://github.com/josephwright/beamer/issues/456 I wanted to reset the section numbers at \part. But this only works for tableofcontents if one also set the count \beamer@tocsectionnumber to zero. Would it be possible to have a better interface?

\documentclass[]{beamer}
\useinnertheme{rounded}
\makeatletter
\@addtoreset{section}{part}
\makeatletter
\begin{document}
\part{Part 1}

\begin{frame}
  \frametitle{Toc Part \thepart}
  \tableofcontents
\end{frame}

\section{Section 1}

\begin{frame}
\frametitle{Frametitle}
Content section \thesection
\end{frame}

\part{Part 2}
%\makeatletter \beamer@tocsectionnumber=0 \makeatother %needed

\begin{frame}
 \frametitle{Toc Part \thepart}
 \tableofcontents %wrong number
\end{frame}

\section{Section 1}


\begin{frame}
\frametitle{Frametitle}
Content section \thesection
\end{frame}

\end{document}