Problem with uline and table-format in siunitx table

I asked a previous question about underlining data in a table when using the siunitx S column definition (see Use of underline and siunitx in a table). The advice given was perfect until I added \sisetup{table-format=2.1} to reduce the amount of space being used up the numbers. I have managed to get my table spaced out perfectly now, so I don't really want to remove the \sisetup, but this line means that any underlined values in the table are now not aligned by decimal point.

Is there any way to combine underlining with this \sisetup?

MWE:

\documentclass{article}
\usepackage{etoolbox,siunitx,booktabs,threeparttable,multirow,array,graphicx}
\usepackage[normalem]{ulem}
\robustify\bfseries
\robustify\uline
\sisetup{detect-weight        = true,
detect-inline-weight = math,
tight-spacing        = true,
table-format         = 2.1,
}

\begin{document}
\begin{table}
\caption{Insert caption here}
\centering
\begin{threeparttable}[b]
\begin{tabular}{SS}
\toprule
{Column 1} & {Column 2}\\
\midrule
7.1 & 4.2\\
\uline{8.7} & 6.5\\
9.3 & \uline{1.0}\\
\bottomrule
\end{tabular}
\end{threeparttable}
\end{table}
\end{document}

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