Multiline \institute has no spacing in Beamerposter footline

Question

I've implemented a custom theme to provide institute information in the footline of my poster. It works fine in practice, but the spacing between lines is way off if the lines don't include characters that go above and below the basic line height, i.e. the height of say "e". So I've resorted in a phantom-reverse-phantom command to force high and low letters. However, when I insert the institute in normal text or a similar environment outside the footline, the spacing is fine. Am I missing something? Removing the surrounding minipage helps too, but I want to restrict the width. And again, no such issue with the minipage outside of the footline either.

Here's my MWE:

\documentclass[final,hyperref={pdfpagelabels=false}]{beamer}
\usepackage[orientation=portrait,size=a0,scale=2,debug]{beamerposter}
\mode<presentation>{\usetheme{cvprl}}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
% Use phantom and reverse with negphantom to enforce consistent spacing between text rows
% that don't have characters that would dip below or rise above normal text.
\newcommand{\cvprlnegphantom}[1]{\settowidth{\dimen0}{#1}\hspace*{-\dimen0}}
\newcommand{\cvprlaligntext}{\phantom{Tj}\cvprlnegphantom{Tj}}
\institute{
    lots\
    of\
    institutes\
}
%\institute{
%    \cvprlaligntext lots\
%    \cvprlaligntext of\
%    \cvprlaligntext institutes\
%}
\begin{document}
\begin{frame}
\insertinstitute
% Footline duplicate
\begin{beamercolorbox}[wd=\paperwidth]{footline}
\begin{columns}[T]
\begin{column}{\paperwidth}
    \begin{beamercolorbox}[wd=\textwidth]{footlinesep}\vspace{1em}\end{beamercolorbox}
    \vskip 2em
    \centering
    \begin{minipage}{0.95\textwidth}
        \usebeamercolor{institute}{\color{fg}\large{\insertinstitute}\[1ex]}
    \end{minipage}
\end{column}
\end{columns}
\end{beamercolorbox}
\end{frame}
\end{document}
% beamerthemecvprl.sty:
\ProvidesPackage{cvprl}
\mode<all>
\setbeamercolor{footline}{fg=black}
\setbeamercolor{footlinesep}{fg=white,bg=black}
\setbeamercolor{institute}{fg=black}
\setbeamertemplate{footline}{
    \begin{beamercolorbox}[wd=\paperwidth]{footline}
    \begin{columns}[T]
    \begin{column}{\paperwidth}
        \begin{beamercolorbox}[wd=\textwidth]{footlinesep}\vspace{1em}\end{beamercolorbox}
        \vskip 2em
        \centering
        \begin{minipage}{0.95\textwidth}
            \usebeamercolor{institute}{\color{fg}\large{\insertinstitute}\[1ex]}
        \end{minipage}
    \end{column}
    \end{columns}
    \end{beamercolorbox}
}

Here's how the main content looks like:

And here's the footline:

What could I do to fix this? I really dislike hacking the system like this.