In-text floats vs bottom floats: how to get consistent spacing?

Since the 2025-06-01 LaTeX kernel update, the new socket build/column/baselineattach lets us attach bottom floats using the baseline of the last text line. With \AssignSocketPlug{build/column/baselineattach}{on}, \textfloatsep is now added from the baseline and descenders in the last line no longer affect the spacing.

However, \intextsep is still measured from the depth of the last line, not from the baseline. So the vertical space above an h-float changes depending on whether the previous line contains descenders. This produces inconsistent spacing between h-floats and b-floats.

In the example image below, the spacing between a paragraph without descenders and an in-text float is 4.25 mm, while with a descender in the last line it becomes 4.94 mm. In contrast, the spacing to a b-float (which uses \textfloatsep and is affected by the socket baselineattach) matches the first value (within measurement uncertainty), confirming that only \intextsep still behaves differently.

Is it possible to patch the output routine so that \intextsep behaves like \textfloatsep, i.e., is also attached to the baseline?

I attempted to patch the output routine command \@addtocurcol directly by inserting a negative space equal to \theprevdepth, but this failed with compilation errors — presumably because \theprevdepth is not available at that point in the output routine.

Here is a MWE :

\documentclass{article}

\setlength{\textfloatsep}{\intextsep}
\AssignSocketPlug{build/column/baselineattach}{on}
\AssignSocketPlug{build/column/outputbox}{floats-space-footnotes}
\raggedbottom

\begin{document}

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\begin{figure}[h]
    \rule{\textwidth}{2cm}
\end{figure}

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\begin{figure}[h]
    \rule{\textwidth}{2cm}
\end{figure}

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur dictum gravida mauris. Nam arcu libero, nonummy eget, consectetuer id, vulputate a, magna. Donec vehicula augue eu neque.

\begin{figure}[b]
    \rule{\textwidth}{2cm}
\end{figure}
\end{document}