Modificar la distancia de entrada de la materia secundaria de ToC

Question

Creé un documento simple usando memoirla clase de la siguiente manera:

\documentclass[12pt,a5paper]{memoir}

\renewcommand\thepart{\arabic{part}}
% modify ToC part
\renewcommand{\cftpartaftersnum}{.}
\renewcommand{\cftpartfont}{\normalsize\bfseries}
\renewcommand{\cftpartpagefont}{\normalsize\bfseries}
\setlength{\cftbeforepartskip}{16pt}
\setlength{\cftpartnumwidth}{2.5em}
% modify ToC chapter
\renewcommand{\cftchapteraftersnum}{.}
\renewcommand{\cftchapterfont}{\normalsize}
\renewcommand{\cftchapterleader}{\cftdotfill{\cftdotsep}}
\renewcommand{\cftchapterpagefont}{\normalsize}
\setlength{\cftbeforechapterskip}{2pt}
\setlength{\cftchapternumwidth}{2.5em}


\begin{document}
\frontmatter
\tableofcontents
\mainmatter

\part{Part One}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\part{Part Two}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\backmatter
\pagestyle{plain}
\chapter[About Writer]{About Writer}

\end{document}

¿Cómo puedo agregar más espacio (digamos 16 puntos) entre About Writery el último capítulo en ToC (como los que están entre Part Oney Part Two)? Gracias.

ACTUALIZACIÓN: AmbosKarlkoeller'syjohannes_bLas respuestas funcionaron bien si usaba \chapter[About Writer]{About Writer}. Pero cuando usé \include{aboutwriter}(como @barbara-beetonmencionado), no funcionaron.

\documentclass[12pt,a5paper]{memoir}

\renewcommand\thepart{\arabic{part}}
% modify ToC part
\renewcommand{\cftpartaftersnum}{.}
\renewcommand{\cftpartfont}{\normalsize\bfseries}
\renewcommand{\cftpartpagefont}{\normalsize\bfseries}
\setlength{\cftbeforepartskip}{16pt}
\setlength{\cftpartnumwidth}{2.5em}
% modify ToC chapter
\renewcommand{\cftchapteraftersnum}{.}
\renewcommand{\cftchapterfont}{\normalsize}
\renewcommand{\cftchapterleader}{\cftdotfill{\cftdotsep}}
\renewcommand{\cftchapterpagefont}{\normalsize}
\setlength{\cftbeforechapterskip}{2pt}
\setlength{\cftchapternumwidth}{2.5em}

% Karlkoeller said:
\usepackage{etoolbox}
\appto{\backmatter}{\addtocontents{toc}{\protect\addvspace{16pt}}}{}{}

\begin{document}
\frontmatter
\tableofcontents
\mainmatter

\part{Part One}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\part{Part Two}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\backmatter
\pagestyle{plain}
% \chapter[About Writer]{About Writer}

% Johannes_B said:
% \addtocontents{toc}{\protect\vspace{16pt}}

\include{aboutwriter} % Include external file

\end{document}

Answer 1

Cargue el paquete etoolboxy emita

\preto{\backmatter}{\addtocontents{toc}{\protect\addvspace{16pt}}}

De esta manera, cuando se emite \backmatterun 16ptsalto se agrega en el ToC.

MWE:

\documentclass[12pt,a5paper]{memoir}

\renewcommand\thepart{\arabic{part}}
% modify ToC part
\renewcommand{\cftpartaftersnum}{.}
\renewcommand{\cftpartfont}{\normalsize\bfseries}
\renewcommand{\cftpartpagefont}{\normalsize\bfseries}
\setlength{\cftbeforepartskip}{16pt}
\setlength{\cftpartnumwidth}{2.5em}
% modify ToC chapter
\renewcommand{\cftchapteraftersnum}{.}
\renewcommand{\cftchapterfont}{\normalsize}
\renewcommand{\cftchapterleader}{\cftdotfill{\cftdotsep}}
\renewcommand{\cftchapterpagefont}{\normalsize}
\setlength{\cftbeforechapterskip}{2pt}
\setlength{\cftchapternumwidth}{2.5em}

\usepackage{etoolbox}
\preto{\backmatter}{\addtocontents{toc}{\protect\addvspace{16pt}}}


\begin{document}
\frontmatter
\tableofcontents
\mainmatter

\part{Part One}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\part{Part Two}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\backmatter
\pagestyle{plain}
\chapter[About Writer]{About Writer}

\end{document} 

Producción:

Answer 2

El espacio en las partes anteriores proviene \party es más fácil, y creo que lleva a una tabla de contenido más sencilla de entender usar el mismo mecanismo aquí en lugar de simplemente depender del espacio.

\documentclass[12pt,a5paper]{memoir}

\renewcommand\thepart{\arabic{part}}
% modify ToC part
\renewcommand{\cftpartaftersnum}{.}
\renewcommand{\cftpartfont}{\normalsize\bfseries}
\renewcommand{\cftpartpagefont}{\normalsize\bfseries}
\setlength{\cftbeforepartskip}{16pt}
\setlength{\cftpartnumwidth}{2.5em}
% modify ToC chapter
\renewcommand{\cftchapteraftersnum}{.}
\renewcommand{\cftchapterfont}{\normalsize}
\renewcommand{\cftchapterleader}{\cftdotfill{\cftdotsep}}
\renewcommand{\cftchapterpagefont}{\normalsize}
\setlength{\cftbeforechapterskip}{2pt}
\setlength{\cftchapternumwidth}{2.5em}


\begin{document}
\frontmatter
\tableofcontents
\mainmatter

\part{Part One}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}

\part{Part Two}
\chapter[Chapter Title]{Chapter Title}
\chapter[Chapter Title]{Chapter Title}
%\chapter[Chapter Title]{Chapter Title}

\backmatter
\part{The Appendix Bits}
\pagestyle{plain}
\chapter[About Writer]{About Writer}

\end{document}