Simple mini frames under frame title beamer

I have a simple black beamer template for presentations that I often use. I would like to add some simple mini frame navigation to this, but the outer theme for mini frames adds in too much extra stuff (section names, etc).

I want to add miniframe circles beneath the frametitle without any words or separation denoting section changes in the pdf. Just one circle per frame, centered in a thin line underneath the frametitle. But I do want to have sections in the pdf for general navigation when viewing the file.

It would look something like this...

I looked into adapting the code from the outer theme "mini-frame" .sty, but it is beyond my skill.

Here is my MWE:

\documentclass{beamer}
\setbeamertemplate{itemize items}[circle]
\setbeamercolor{itemize item}{fg=black}
\setbeamercolor{frametitle}{fg=white, bg=black}
\setbeamerfont{frametitle}{size=\small}
\usefonttheme{serif}
\begin{document}

\section{Some Amazing Presentation}
\begin{frame}{MWE $\vert$ Some Amazing Presentation}
\begin{itemize}
\item This is a really amazing presentation, demonstrating a MWE
\item Very impressive
\end{itemize}
\end{frame}

\section{The Second Part}
\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item The second part of this presentation is even better
\item It was really worth waiting for
\end{itemize}
\end{frame}

\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item Lots of things to say
\item these things are interesting
\end{itemize}
\end{frame}

\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item blah blah blah
\item la la la
\end{itemize}
\end{frame}

\section{The End}
\begin{frame}{MWE $\vert$ The End}
\begin{itemize}
\item But the end is really the best part
\end{itemize}
\end{frame}

\end{document}


This should work as you expect:

\documentclass{beamer}
\setbeamertemplate{itemize items}[circle]
\setbeamercolor{itemize item}{fg=black}
\setbeamerfont{frametitle}{size=\small}
\usefonttheme{serif}
\setbeamercolor{frametitle}{fg=white,bg=black}

\setbeamercolor{mini frame}{fg=white}

\makeatletter
\hbox to #1{{%
\beamer@currentsubsection=0%
\def\sectionentry##1##2##3##4##5{}%
\def\slideentry##1##2##3##4##5##6{%
\ifnum##6=\c@part\ifnum##2>0\ifnum##3>0%
\beamer@tempdim=-\beamer@vboxoffset%
\multiply\beamer@tempdim by\beamer@ypos%
\raise\beamer@tempdim\hbox to 3pt{
\usebeamerfont{mini frame}%
\ifnum\c@section=##1%
\ifnum\c@subsection=##2%
\usebeamercolor[fg]{mini frame}%
\ifnum\c@subsectionslide=##3%
\usebeamertemplate{mini frame}%\beamer@minislidehilight%
\else%
\usebeamertemplate{mini frame in current subsection}%\beamer@minisliderowhilight%
\fi%
\else%
\usebeamercolor{mini frame}%
%\color{fg!50!bg}%
\usebeamertemplate{mini frame in other subsection}%\beamer@minislide%
\fi%
\else%
\usebeamercolor{mini frame}%
%\color{fg!50!bg}%
\usebeamertemplate{mini frame in other subsection}%\beamer@minislide%
\fi%
}\hskip-10cm plus 1fil%
}
\fi\fi\else%
\fakeslideentry{##1}{##2}{##3}{##4}{##5}{##6}%
\fi
\ignorespaces
}%
#2\hskip.3cm\setbox\beamer@sectionbox=\hbox{}%
\box\beamer@sectionbox\hfil\hskip.3cm%
#3
}}
}
\makeatother

\setbeamertemplate{frametitle}
{\nointerlineskip
\leavevmode
\vbox{%
\begin{beamercolorbox}[wd=\paperwidth,ht=3ex,dp=1ex]{frametitle}%
\raggedright\hspace*{1em}\insertframetitle
\end{beamercolorbox}\nointerlineskip
\begin{beamercolorbox}[wd=\paperwidth,ht=1ex,dp=1ex]{frametitle}%
\end{beamercolorbox}
}%
}

\begin{document}
\section{Some Amazing Presentation}
\subsection{Subsection 1}
\begin{frame}{MWE $\vert$ Some Amazing Presentation}
\begin{itemize}
\item This is a really amazing presentation, demonstrating a MWE
\item Very impressive
\end{itemize}
\end{frame}

\section{The Second Part}
\subsection{Subsection 1}
\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item The second part of this presentation is even better
\item It was really worth waiting for
\end{itemize}
\end{frame}

\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item Lots of things to say
\item these things are interesting
\end{itemize}
\end{frame}

\begin{frame}{MWE $\vert$ The Second Part}
\begin{itemize}
\item blah blah blah
\item la la la
\end{itemize}
\end{frame}

\section{The End}
\subsection{Subsection 1}
\begin{frame}{MWE $\vert$ The End}
\begin{itemize}
\item But the end is really the best part
\end{itemize}
\end{frame}
\end{document}


The above solution needs:

1. A rewrite of the default mini frame navigation so that no section names are printed (the part between \makeatletter and \makeatother).
2. A custom frame title template that embeds the new navigation system (the \setbeamertemplate{frametitle} macro).

Note that in your MWE there were no subsections, which are necessary for the mini frame navigation to work properly. If you don't want/need subsections, just introduce a dummy single subsection for every section (you can also exclude it from the toc).

With a single subsection for section greyed out bullets will indicate frames from other sections, since every section contains a single subsection.