Highlighting inside NiceTabular causes boxes to go outside rules

Question

I tried to duplicate the result of the table in How to create a multirow red box for highlighting table results? using NiceTabular and tikz. The solution works well as long as cell-space-limits is small. When increasing it, the result becomes

As you see, the box is very close to the contents of the second row and exceeds the bottomrule. One workaround is to add \addlinespace, but this is suboptimal solution because sometimes we might clearly see how rows spacing differs. Is it possible to get a better one?

\documentclass{article}

\usepackage{booktabs}
\usepackage[x11names]{xcolor}

\usepackage{tikz}
\usetikzlibrary{fit}

\usepackage{nicematrix}
\NiceMatrixOptions{cell-space-limits=1.1mm}

\begin{document}
    
\begin{table}[h]
    \caption{Box Test}
    \centering
    \begin{NiceTabular}{cccc}
          & A & B & C \\ \toprule
        I & 1 & 2 & 3 \\
        J & 4 & 5 & 6 \\
        K & 7 & 8 & 9 \\ \bottomrule
        \CodeAfter
        \tikz \node [draw=Coral3, fit = (3-1) (4-2)] { } ;
    \end{NiceTabular}
\end{table}

\begin{table}[h]
    \caption{Box Test}
    \centering
    \begin{NiceTabular}{cccc}
          & A & B & C \\ \toprule
        I & 1 & 2 & 3 \\ \addlinespace
        J & 4 & 5 & 6 \\
        K & 7 & 8 & 9 \\ \addlinespace \bottomrule
        \CodeAfter
        \tikz \node [draw=Coral3, fit = (3-1) (4-2)] { } ;
    \end{NiceTabular}
\end{table}
    
\end{document}

Answer 1

You could try to use the key inner ysep of Tikz in the node:

\documentclass{article}
\usepackage{booktabs}
\usepackage[x11names]{xcolor}

\usepackage{tikz}
\usetikzlibrary{fit}

\usepackage{nicematrix}
\NiceMatrixOptions{cell-space-limits=1.1mm}

\begin{document}
    
\begin{table}[h]
    \caption{Box Test}
    \centering
    \begin{NiceTabular}{cccc}
          & A & B & C \\ \toprule
        I & 1 & 2 & 3 \\
        J & 4 & 5 & 6 \\
        K & 7 & 8 & 9 \\ \bottomrule
        \CodeAfter
        \tikz \node [inner ysep = -0.9mm, draw=Coral3, fit = (3-1) (4-2)] { } ;
    \end{NiceTabular}
\end{table}
\end{document}