KOMA script: Appendix sections A1.1, A1.2, ... A2.1 and uppercase TOC chapter entries

I use xelatex with KOMA script class scrreprt.Now I have to number my thesis appendices as sections A1.1, A1.2 and subsections A1.1.1, and so on. Chapter entries in the TOC including chapter APPENDICES should be set uppercase.

Therefore, I redefined the \thesection and \thesubsection. The hyperref option hypertexnames=false makes sure that the links are linked correctly.But now I want the TOC entries A1.1, ... aligned with the normal sections and subsections numbers like:

 1.1 Section     1.1.1 SubsectionA1.1 Appendix Section    A1.1.1 Appendix Subsection

Setting the main font Verdana with fontspec additionally leads to reduced spacing between A1.1 and the corresponding TOC entry:

This might by caused by not defining A as an appedix prefix.

Further, I tried to make the TOC chapter entries uppercase with:

\addtokomafont{chapterentry}{\MakeUppercase} 

But this produces error messages for the .toc file. Somehow this works fine for chapter titles in the text itself and also \nameref chapter is not uppercase as intended.

I hope anyone can help me with the appendix entry alignment and the uppercase chapter entry. Thank you in advance!

Here is my MWE:

% !TEX TS-program = xelatex\documentclass[a4paper,10pt,]{scrreprt}\usepackage[no-math]{fontspec}\PassOptionsToPackage{no-math}{fontspec}\usepackage{footnotebackref}\usepackage[showframe]{geometry}\setmainfont[BoldFont={Verdanab.ttf},ItalicFont={Verdanai.ttf}]{Verdana.ttf} % <<< Reduces spacing in toc entries\setlength{\parindent}{0pt}% Chapter title\setkomafont{chapter}{\Large\normalfont\bfseries\MakeUppercase}\RedeclareSectionCommand[beforeskip=0pt]{chapter}% TOC entry chapter level\RedeclareSectionCommand[toclinefill=\TOCLineLeaderFill]{chapter}\setkomafont{chapterentry}{\normalfont\bfseries}%\addtokomafont{chapterentry}{\MakeUppercase} % <<< This does not work% Section title\setkomafont{section}{\large\normalfont\bfseries}% Subsection/Subsubsection title\setkomafont{subsection}{\normalsize\normalfont\bfseries}\hypersetup{     hypertexnames=false,    colorlinks=true,    citecolor=black,    linkcolor=black,    urlcolor=black,    bookmarksnumbered,    bookmarksdepth=2,    bookmarksopenlevel=1,    bookmarksopen=true,} \begin{document}\tableofcontents\chapter{Main Body}Reference to appedix \ref{app: First Appendix} or sub-appendix \ref{app: First Sub-Appendix}\section{Section}\subsection{Subsetion}\chapter{Appendices}\renewcommand{\thesection}{A\arabic{chapter}.\arabic{section}}\renewcommand{\thesubsection}{A\arabic{chapter}.\arabic{section}.\arabic{subsection}}\renewcommand{\thesubsubsection}{A\arabic{chapter}.\arabic{section}.\arabic{subsection}.\arabic{subsubsection}}\setcounter{chapter}{1}\setcounter{section}{0}\setcounter{subsection}{0}\setcounter{subsubsection}{0}\section{First Appendix} \label{app: First Appendix}\subsection{Fist Sub-Appendix} \label{app: First Sub-Appendix}\end{document}