Replacing "and" by "&" (ampersand) for \parencite in authoryear-icomp

Question

I currently use the authoryear-icomp style with the biblatex package. By default, the citations are done as follows:

• using \citeauthor{Butler.2012}: Butler and Ekdahl
• using \parencite{Butler.2012}: (Butler and Ekdahl, 2012)
• within in the bibliography: Butler, Nancy Evelyn and Elizabeth Muriel Ekdahl (2012) [...]

Is it possible to adjust the style so that \parencite{Butler.2012} produces "(Butler & Ekdahl, 2012)", while the other citing styles still use the word "and" instead of an ampersand?

I tried redefining the and keyword:

\DefineBibliographyStrings{english}{
    and = {\&}            
}

But this of course leads to the case where all "and"s are replaced by "&".

Edit: Minimal working example:

\documentclass{scrartcl}

\usepackage[backend=biber,%
style=authoryear-icomp,%
natbib=true,%
hyperref=true,%
useprefix=true,%
minnames=1,%
maxnames=2]{biblatex}

\DefineBibliographyStrings{english}{ %
    and = {\&}%
}

\addbibresource{testbib.bib}

\begin{document}
\citeauthor{Butler.2012}

\parencite[5]{Butler.2012}

\printbibliography
\end{document}

Using the bibliography file testbib.bib:

@book{Butler.2012,
 author = {Butler, Nancy Evelyn and Ekdahl, Elizabeth Muriel},
 year = {2012},
 title = {{Aprenda Terena Vol. 1}},
 url = {https://www.sil.org/resources/archives/75521},
 urldate = {2022-02-24},
 edition = {Edição Online},
 publisher = {{Associação Internacional de Linguística – SIL Brasil} and {SIL International}},
 origdate = {1979},
 location = {Anápolis, GO},
 organization = {{Associação Internacional de Linguística – SIL Brasil}},
 editor = {Bridgeman, Loraine Irene}
}

Answer 1

Use that finalnamedelim (the delimiter inserted between the last two names in a name list) is context sensitive and thus can get different definitions for \parencite and everywhere else.

\documentclass{scrartcl}

\usepackage[backend=biber,
  style=authoryear-icomp,
  natbib=true,
  useprefix=true,
  minnames=1,
  maxnames=2]{biblatex}

\DeclareDelimFormat[parencite]{finalnamedelim}{\addspace\&\space}

\addbibresource{biblatex-examples.bib}

\begin{document}
\citeauthor{sigfridsson}

\parencite[5]{sigfridsson}

\printbibliography
\end{document}