\documentclass[12pt]{article}


\usepackage{l3benchmark}

\PassOptionsToPackage{cache}{groupthm}

\usepackage[number in = section]{fancythm}

\makeatletter
%\@counteralias{insection}{indocument}
\makeatother


\AddProvidedFancyTheoremToGroup{lemma}{small}

\NewTheoremGroup[suffix = $\frac{3}{4}$]{gag}

\NewGroupedTheoremFamily[group = {dagger, star, gag}]{definition}

\NewGroupedTheoremFamilyOptions{definition}{!s !t+ !tg }
{
  \IfBooleanT{#3} { \AddTheoremToGroup{gag}}
}


\ExplSyntaxOn
\benchmark_once:n
  {
%      \__groupthm_thmtools_declare_theorem:nn{name=Definition}{__definition__groups_}
  }
\ExplSyntaxOff


\begin{document}

\begin{definition}g
  bla
\end{definition}

\section{test}

\stepcounter{toplevel}


\begin{example}
  test
\end{example}

\begin{example}+
  test
\end{example}

\begin{example}*
  
\end{example}

\begin{lemma}
  
\end{lemma}

\begin{definition}
  test
\end{definition}

\begin{definition}*
  bla
\end{definition}

\begin{theoremdef}
  test
\end{theoremdef}



\begin{goal}+
  test
\end{goal}


\end{document}