Using \emph{\relax About} to emphasize but not caps-protect “About”, as recommended by https://tex.stackexchange.com/a/140071/22851 does not work as expected: it removes the emphasis but keeps the caps-protection:
\documentclass[american]{article}
\usepackage[american]{babel}
\usepackage[autostyle]{csquotes}%
\usepackage[backend=biber, style=apa]{biblatex}
\DeclareLanguageMapping{american}{american-apa}
\usepackage{fontspec}
\setmainfont{Linux Libertine}
\usepackage{filecontents}
%
\begin{filecontents}{\jobname.bib}
@article{a,
author = {Doe, John},
year = {2015},
title = {All About \emph{About} 1}
}
@article{b,
author = {Doe, John},
year = {2015},
title = {All About \emph{\relax About} 2}
}
\end{filecontents}
%
\addbibresource{\jobname.bib}
\begin{document}
\cite{a, b}
\printbibliography
\end{document}
Output:
Doe, 2015a, 2015b
References
Doe, J. (2015a). All about About 1.
Doe, J. (2015b). All about About 2.
So, what would work?
