多色环境中 tcolorboxes 的垂直“对齐”

Question

我正在制作带有可破坏的 tcolorboxes 和 multicols 的练习纸。

当箱子破损时，它会尽可能地落到其所在列的最底部，这是完美的。然而，对于没有破损的箱子来说，情况并非如此。

我想要一种垂直对齐方式，使我的框占据整个可用的垂直空间。这样，我的所有最后框都会在列的底部对齐，无论是否破碎。

有人可以帮我做到这一点吗？

我的代码的MWE：

\documentclass[a4paper, twoside=semi, 11pt, DIV=16,listof=entryprefix,headings=openright]{scrbook}



\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}
\usepackage{lmodern}
\usepackage{setspace}
\usepackage[most,many,listings,skins]{tcolorbox}
\tcbuselibrary{breakable}
\usepackage{varwidth}
\usepackage[autooneside=false]{scrlayer-scrpage}
\usepackage{multicol}



\setlength{\parindent}{0cm}
\onehalfspacing


\newcommand{\dum}{This is a sentence of dummy text. }




\setkomafont{disposition}{\bfseries\sffamily}
\addtokomafont{pagenumber}{\sffamily}
\automark[chapter]{chapter}
\pagestyle{scrheadings}
\renewcommand*{\headfont}{\itshape\sffamily}


\newcounter{compteur}[chapter]


\newtcolorbox[use counter*=compteur]{exo}[1]{varwidth boxed title=15cm,breakable, enhanced, colback=black!0,colframe=black!20,adjusted title=\label{\thecompteur}Exercice \thecompteur #1,coltitle=black,fonttitle=\small\bfseries\sffamily,before skip=0.1cm,attach boxed title to top left={xshift=-0mm,yshift*=-6.22mm},boxed title style={sharp corners=uphill,right=0mm,left=0mm,boxsep=0.5mm,colback=black!20,colframe=black!20},pad at break=1.5mm, break at=-\baselineskip/0pt}

\begin{document}
\chapter{Exercises}
\begin{multicols*}{2}


\begin{exo}{}
 \dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}
\begin{exo}{}
\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum
\dum\dum\dum\dum\dum\dum
\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum
\end{exo}

\begin{exo}{}
\dum\dum\dum\dum
\end{exo}



\end{multicols*}
\end{document}