scrbook no chapterheadstartvskip for unnumbered chapter

Question

I am writing a document using the KOMA-Script scrbook class. I am using a custom chapter style and a \chapterheadstartvskip. The chapter number is printed as a tikz overlay in the resulting whitespace. For unnumbered chapters (Contents, Bibliography), this results in a large empty whitespace that I want to eliminate.

I have tried setting \chapterheadstartvskip to 0 and add the \vspace to the start of my redefinition of \chapterformat, but this \vspace seems to have no effect.

Is there a way to have different \chapterheadstartvskip for numbered and unnumbered chapters?

MWE:

\documentclass[BCOR=15mm, DIV=8]{scrbook}

\KOMAoptions{
    headings=twolinechapter,
    chapterprefix=false,
    numbers=noenddot
}

\usepackage{typearea}
\usepackage[utf8]{inputenc}
\usepackage{kpfonts}
\usepackage[T1]{fontenc}
\usepackage{microtype}
\usepackage{lipsum}
\usepackage{filecontents}
\usepackage[
    backend=biber,
    style=numeric-comp,
    sorting=none,
    doi=false,
    url=false,
    isbn=false,
    maxbibnames=99,
    maxcitenames=99,
    giveninits=true,
    backref=true
]{biblatex}

\usepackage{tikz}
\usetikzlibrary{
    calc,
    positioning}
\tikzset{>=latex}
\usepackage{tikzpagenodes}

\usepackage{etoolbox}
\usepackage{xstring}
\usepackage{calc}

\definecolor{laccentcolor}{HTML}{d3d3d3}

\addtokomafont{disposition}{\rmfamily}

\addtokomafont{chapter}{\scshape\LARGE}

\newif\ifappendix

\def\chaplengths{{11mm,6mm,7mm,2.5mm,7mm,5mm,6mm,7mm,6.5mm}}
\def\applengths{{4mm,8.5mm,6mm}}
\renewcommand*{\chapterformat}{%
\begin{tikzpicture}[remember picture]
\coordinate (mychapanchor-\arabic{chapter});
\end{tikzpicture}
\begin{tikzpicture}[remember picture, overlay]
    \pgfmathsetmacro{\mylength}{\ifappendix\applengths[\arabic{chapter}-1]\else\chaplengths[\arabic{chapter}-1]\fi}
    \node[anchor=south east,xshift=\mylength,
          inner sep=0, outer sep=0]
          at ([yshift=1.2cm]mychapanchor-\arabic{chapter}-| current page text area.east){%
        \fontsize{10cm}{10cm}\selectfont%
        \textcolor{laccentcolor}{\thechapter}%
    };
    % alignment line
    % \draw[thin] (current page text area.north east)
    %     -- (current page text area.south east);
\end{tikzpicture}%
}
\renewcommand*{\chapterheadstartvskip}{\vspace*{9cm}}

\begin{filecontents}{bibliography.bib}
@article{cava1987oxygen,
  title={Oxygen stoichiometry, superconductivity and normal-state
         properties of YBa2Cu3O7--$\delta$},
  author={Cava, RJ and Batlogg, B. and Chen, CH and Rietman, EA and
          Zahurak, SM and Werder, D.},
  journal={Nature},
  volume={329},
  number={6138},
  pages={423--425},
  year={1987},
  publisher={Nature Publishing Group}
}

@book{sterner2002ecological,
  title={Ecological stoichiometry: the biology of elements from
         molecules to the biosphere},
  author={Sterner, R.W. and Elser, J.J.},
  year={2002},
  publisher={Princeton Univ Pr}
}

@article{castro1975cortazar,
  title={Cort{\'a}zar, Surrealism, and Pataphysics},
  author={Castro-Klaren, S.},
  journal={Comparative Literature},
  volume={27},
  number={3},
  pages={218--236},
  year={1975},
  publisher={JSTOR}
}

@inproceedings{munro1992deterministic,
  title={Deterministic skip lists},
  author={Munro, J.I. and Papadakis, T. and Sedgewick, R.},
  booktitle={Proceedings of the third annual ACM-SIAM symposium on
             Discrete algorithms},
  pages={367--375},
  year={1992},
  organization={Society for Industrial and Applied Mathematics}
}

@book{Jones-2002,
   author = {Jones, Christopher A. and Drake, Fred L.},
   title = {Python and XML},
   publisher = {O'Reilly},
   address = {Sebastopol, Calif.},
   edition = {1st},
   keywords = {Python (Computer program language)
XML (Document markup language)},
   pages = {xvi, 360 p.},
   year = {2002}
}
\end{filecontents}

\addbibresource{bibliography.bib}

\begin{document}

\frontmatter

\tableofcontents

\mainmatter

\chapter{A Fancy Chapter Name to Test the Formatting}
\lipsum[1]

\appendix\appendixtrue

\chapter{A Fancy Chapter Name to Test the Formatting}
\lipsum[1]

\backmatter

\nocite{*}
\printbibliography[heading=bibintoc]

\end{document}

Answer 1

As @Schweinebacke mentioned in a comment: The main problem is the hidden height of \chapterformat. Additionally you do not need package tikzpagenodes and all the remember picture stuff.

Remove chapterprefix=false and use headings=twolinechapter or chapterprefix=true.

\documentclass[BCOR=15mm, DIV=8]{scrbook}
\KOMAoptions{
    headings=twolinechapter,
    numbers=noenddot
}
%\usepackage[utf8]{inputenc}% not needed with an uptodate TeX distribution
\usepackage{kpfonts}
\usepackage[T1]{fontenc}
\usepackage{microtype}
\usepackage{lipsum}

\usepackage{tikz}
\definecolor{laccentcolor}{HTML}{d3d3d3}

\addtokomafont{disposition}{\rmfamily}
\addtokomafont{chapter}{\scshape\LARGE}

\newif\ifappendix

\def\chaplengths{{11mm,6mm,7mm,2.5mm,7mm,5mm,6mm,7mm,6.5mm}}
\def\applengths{{4mm,8.5mm,6mm}}
\renewcommand*{\chapterformat}{%
  \hfill\begin{tikzpicture}
    \pgfmathsetmacro{\mylength}{\ifappendix\applengths[\arabic{chapter}-1]\else\chaplengths[\arabic{chapter}-1]\fi}
    \node(n)[inner sep=0, outer sep=0,
        font=\fontsize{10cm}{10cm}\selectfont,
        text=laccentcolor
      ]{\rule{0pt}{\ht\strutbox}\thechapter};
    \pgfresetboundingbox
    \useasboundingbox(n.south west)rectangle([xshift=-\mylength]n.north east);% bounding box with a fixed height
\end{tikzpicture}%
}


\begin{document}
\frontmatter
\tableofcontents
\mainmatter
\chapter{A Fancy Chapter Name to Test the Formatting}
\lipsum[1]
\appendix\appendixtrue
\chapter{A Fancy Chapter Name to Test the Formatting}
\lipsum[1]
\end{document}

Result:

Additional remarks: Do not load package typearea manually in your code. The KOMA-Script class does this automatically. Option chapterprefix=false does the same as headings=onlinechapter and therefore overwrites headings=twolinechapter. So you have to remove this option.

The vertical space above the chapter heading and between the number and the title can be adjusted to your needs using options beforeskip and innerskip of \RedeclareSectionCommand, eg:

\RedeclareSectionCommand[
  beforeskip=0pt,
  afterindent=true,
  innerskip=\baselineskip
]{chapter}

---

Update

Suggestion for \chapterformat without a tikzpicture:

\def\chaplengths{{11mm,6mm,7mm,2.5mm,7mm,5mm,6mm,7mm,6.5mm}}
\def\applengths{{4mm,8.5mm,6mm}}
\renewcommand*{\chapterformat}{%
  \pgfmathsetmacro{\mylength}{\ifappendix\applengths[\arabic{chapter}-1]\else\chaplengths[\arabic{chapter}-1]\fi}%
  \hfill
  \makebox[\dimexpr\width-\mylength pt\relax][l]{%
    \fontsize{10cm}{10cm}\selectfont
    \rule{0pt}{\ht\strutbox}%
    \textcolor{laccentcolor}{\thechapter}%
  }%
}