Kerns added by \textcoquote cause microtype to not see quotation mark properly

[fredrikpaues]

Description

When I compile the minimal example below, which uses microtype and biblatex with the american language option, using LuaLaTeX, then closing quotation marks in the bibliography don't protrude into the right margin.

If I remove csquotes then quotation marks protrude, but then biblatex issues a warning.

I have posted a question regarding this over at Stack Exchange previously. And, before I realized that there was a public repo also for csquotes and that the root cause was in this package, I posted issues in the bug trackers of biblatex and microtype.

@moewew noted in the biblatex issue that "the kerns added by csquotes \textcoquote cause microtype to no longer see the quotation mark properly".

Minimal example demonstrating the issue

\documentclass[american]{article}
\usepackage[
  style=authoryear,
  backend=biber,
  dashed=false,
]{biblatex}

\setlength{\bibhang}{0pt}

\usepackage{filecontents}
\begin{filecontents*}{mwe.bib}
  @article{andersson2011,
    title={An article title that ought to have a closing quotation mark that protrudes iiinto the margin},
    author={Anderson, A Lengthy List of First Names to Move the Article Title to the Next Line},
    journaltitle={Review of Utter Nonsense},
    date={2011},
    volume={5},
  }

  @article{andersson2021,
    title={An article title that ought to have a closing quotation mark that protrudes iiiinto the margin},
    date={2021},
    volume={40},
    crossref={andersson2011}
  }
\end{filecontents*}

\addbibresource{mwe.bib}

\usepackage[showframe, text={140mm, 230mm}]{geometry}
\usepackage{babel}
\usepackage[babel]{microtype}
\usepackage[babel]{csquotes}

\begin{document}
  \noindent ``We see that quotation marks protrude into the right margin when outside the bibliography.''

  \nocite{andersson2021,andersson2011}

  \printbibliography
\end{document}

[fredrikpaues]

I just realized that @moewew provided a better minimal working example that reproduces the issue without throwing biblatex into the mix.

\documentclass[british, american]{article}
\usepackage[showframe, text={140mm, 230mm}]{geometry}
\usepackage{babel}
\usepackage[babel]{microtype}
\usepackage[autostyle]{csquotes}

\begin{document}
  Lorem

  ``We see that quotation marks protrude the right margin when outside the bibliography.''

  \enquote{We see that quotation marks protrude the right margin when outside the bibliography.}

  \textooquote We see that quotation marks protrude the right margin when outside the bibliography.\textcoquote

  \selectlanguage{british}
  ipsum

  `We see that quotation marks protrude the right margin when outside the bibliography.'

  \enquote{We see that quotation marks protrude the right margin when outside the bibliography.}

  \textooquote We see that quotation marks protrude the right margin when outside the bibliography.\textcoquote

  dolor

  `We see that quotation marks protrude the right margin when outside the ``bibliography'' blob'

  \enquote{We see that quotation marks protrude the right margin when outside the \enquote{bibliography} blob}

  \textooquote We see that quotation marks protrude the right margin when outside the \textoiquote bibliography\textciquote{} blob\textcoquote
\end{document}