`function` 函数的 `added` 键值报错 about cus HOT 3 CLOSED

\DocumentMetadata{}
\documentclass{cusdoc}

\hypersetup{pdfauthor={夏大鱼羊},
  pdftitle= Now-Learn-English 手册,
  pdfcreator={\XeLaTeX} with hyperref and Now-Learn-English}

\usepackage{transparent}
\newsavebox\WaterMarkBox
\sbox{\WaterMarkBox}{\rotatebox{45}{\transparent{0.2}\includegraphics[width = 15cm, ]{../assets/logo.png}}}
\background+[./watermark]{\copy\WaterMarkBox}

\newindextype[auto=true,filename=\jobname.idx,heading*={\section}]{\empty}
\setupindex[\empty,docchange]{auto=false}

\makeatletter
\protected\def\normalsize{%
  \@setfontsize \normalsize {10.53937}{12.64725}%
  \abovedisplayskip 1\p@ \@plus 4\p@ \@minus 2\p@ 
  \abovedisplayshortskip \z@ \@plus 2\p@ 
  \belowdisplayskip \abovedisplayskip 
  \belowdisplayshortskip \abovedisplayshortskip
  \let \@listi \@listI
}
\makeatother

\def\nofuncskip{\par\vskip-\bigskipamount\vskip\parskip\par}
\def\zhslash{／}
\newcommand\UNEXPANDEDRESULT{最终结果使用 \tn{unexpanded} （\cs{exp_not:n}）包裹起来。}

\raggedbottom \hfuzz=2.5pt \vfuzz=10pt 


\title{Now-Learn-English \LaTeX 模板使用手册}
\author{夏大鱼羊}
\date{\zhtoday\quad v0.2}

\enablecombinedlist 

\begin{document}

\usepagestyle{totalempty}
\setlength{\lineskiplimit}{4pt}
\setlength{\lineskip}{4pt}

\def\thepage{t.\arabic{page}}
\setuplayout{preset=balance}
\maketitle

\frontmatter
\cusdoctoc

\mainmatter
\usepagestyle{fancy}
\setuptitle[chapter]{numbering=true,pagestyle=fancy}
\removebackground[./watermark]


\begin{function}[type=environment,added=2024-04-17]{point}
  \begin{syntax}
    \verb|\begin{point}| \oarg{point key-val}
    ~~... 
    \verb|\end{point}|
  \end{syntax}
  知识点。
\end{function}


\end{document}