[Tex/LaTex] How to get figure caption to span multiple pages, without having to switch everything to capt-of

captionsfloats

I have found several questions on TeX.SE and elsewhere about making figure captions span multiple pages (e.g., How do I make figure captions span multiple pages?).
I gather that the caption package puts the caption in unbreakable boxes.

Some answers recommend the use of the capt-of package. capt-of seems to work fine, but breaks caption instances. So it seems that using capt-of to enable long figure captions would require me to switch every single caption in my paper to capt-of, which is a burden and seems to eliminate the benefits of floating figures.

Here's a MWE (also on Overleaf) with a figure with short caption and a figure with a long captionof. I would like to be able to have both \usepackage{capt-of}
 and \usepackage[font={small,sf}, singlelinecheck=false]{caption} enabled, and still have my long caption span multiple pages.

\documentclass{article}

% I can't have both caption and capt-of enabled.

% Caption alone doesn't let long captions span multiple pages.    
\usepackage[font={small,sf}, singlelinecheck=false]{caption}

% Capt-of alone would require me to reformat many figures.
\usepackage{capt-of}

% But enabling both breaks capt-of's ability to span captions across pages.

\usepackage{lipsum}

\begin{document} 

\lipsum[1]

% I have many figures that are formatted like this.
\begin{figure}[h!]
   \centering
   \rule{0.3\textwidth}{0.3\textheight}
\caption[Short caption]{\lipsum[1]}
\end{figure}

\lipsum[1-10]

% This seems to be the best way to get long captions to span multiple pages, while being styled like the above figure.
\begin{centering}
\sffamily
   \rule{0.5\textwidth}{0.75\textheight}
\captionof{figure}[short caption]{\lipsum[1-4]}
   \label{figure}
\end{centering}

\end{document}

Alternatively, some way to easily allow captions to span pages without having to re-format would be great.

Best Answer

You don't need the capt-of package which is just one line and the same definition is in caption however caption boxes the caption text so if you want it to break you need to unbox it:

\documentclass{article}

% I can't have both caption and capt-of enabled.

% Caption alone doesn't let long captions span multiple pages.    
\usepackage[font={small,sf}, singlelinecheck=false]{caption}


\usepackage{lipsum}

\begin{document} 

\lipsum[1]

% I have many figures that are formatted like this.
\begin{figure}[h!]
   \centering
   \rule{0.3\textwidth}{0.3\textheight}
\caption[Short caption]{\lipsum[1]}
\end{figure}

\lipsum[1-10]

% This seems to be the best way to get long captions to span multiple pages, while being styled like the above figure.
\begin{center}

   \rule{0.5\textwidth}{0.75\textheight}

\bigskip
\setbox0\vbox{\makeatletter
\let\caption@rule\relax
\captionof{figure}[short caption]{\lipsum[1-4]}
\global\skip1\lastskip\unskip
\global\setbox1\lastbox
}
\unvbox0
\setbox0\hbox{\unhbox1\unskip\unskip\unpenalty
\global\setbox1\lastbox}
\unvbox1
\vskip\skip1



\end{center}

\end{document}
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