How do you center the content of a minipage that is placed inside of a longtabu?

My minipage looks like this and can be found online [here](https://www.sharelatex.com/project/5449fd5cedfa21dd65c8b7de):

```
\begin{minipage}{0.3cm}\tiny{\textbf{T\\e\\x\\t}}\end{minipage}

```

Here is an image of the problem. I want the letteres to be centered and not left aligned.
![enter image description here](https://i.stack.imgur.com/6REKd.png)

```
\documentclass[danish,a4paper,twoside,11pt]{memoir}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{fix-cm}
\usepackage{xcolor}
\usepackage{tabu}
\usepackage{longtable}
\usepackage{enumitem}
\usepackage{multirow}
\usepackage{color, colortbl}
\usepackage{amssymb}
\usepackage{diagbox}

\definecolor{Gray}{gray}{0.9}
\setlrmarginsandblock{3.5cm}{2.5cm}{*}
\setulmarginsandblock{3cm}{*}{1.2}
\checkandfixthelayout[nearest]
\renewcommand{\arraystretch}{1.5}

\begin{document}
\newcolumntype{g}{>{\columncolor{Gray}}X[c]}
\begin{longtabu}{| p{4.2cm} | X[c] | g | g | X[c] | X[c] | g | g | X[c] | X[c] | g | g |}
    \hline \multicolumn{12}{|c|}{\large{Arkitekturvægtning af \textit{use case} 3, 4 og 5}}\\
    \hline \multirow{2}{*}{\begin{minipage}{3cm}\textbf{Kvalitetsattribut}\end{minipage}}          &   
    \multirow{2}{*}{
        \begin{minipage}{0.3cm}
            \tiny\textbf{V\\æ\\g\\t}
        \end{minipage}}   
    & \multicolumn{2}{|c|}{\cellcolor{Gray}\textbf{BP\textsubscript{ED}}}  & \multicolumn{2}{|c|}{\textbf{BP\textsubscript{DDG}}} & \multicolumn{2}{|c|}{\cellcolor{Gray}\textbf{BP\textsubscript{AED}}}  & \multicolumn{2}{|c|}{\textbf{BP\textsubscript{LDS}}}  & \multicolumn{2}{|c|}{\cellcolor{Gray}\textbf{BP\textsubscript{S}}}      \\
     \cline{3-12} & & \tiny Point & \tiny Score &  \tiny Point & \tiny Score &  \tiny Point & \tiny Score &  \tiny Point & \tiny Score &  \tiny Point & \tiny Score\\
     \tabucline[1.3pt]{-}

\end{longtabu}
\end{document}

```