Multiple footnotes in equations in stackrel/overset with hyperref

Question

I'm trying to place more than one footnote over equality sign in align* environment. With one footmark, it's easy:

\begin{align*}
x\overset{\footnotemark}{=}y
\end{align*}
\footnotetext{Comment1}

That's fine. So, I thought that when I add more footnotes, latex will automatically understand me:

\begin{align*}
x\overset{\footnotemark}{=}y\overset{\footnotemark}{=}z
\end{align*}
\footnotetext{Comment1}
\footnotetext{Comment2}

But it didn't, of course. After a while I modified it:

\begin{align*}
x\overset{\footnotemark[1]}{=}y\overset{\footnotemark[2]}{=}z
\end{align*}
\footnotetext[1]{Comment1}
\footnotetext[2]{Comment2}

And it worked! Sort of.... First of all, I'm using hyperref, and these footnotes are not linked. Secondly, when I try creating a new footnote:

\begin{align*}
x\overset{\footnotemark[1]}{=}y\overset{\footnotemark[2]}{=}z
\end{align*}
\footnotetext[1]{Comment1}
\footnotetext[2]{Comment2}

And now for something completely different\footnote{Python, M.}.

it messed up numbering.

Moreover, inserting footnotes manuually does not print them:

\begin{align*}
x\overset{\footnote{Comment1}}{=}y\overset{\footnote{Comment2}}{=}z
\end{align*}

(the links are, but there are no footnotes).

Is there any neat way to do what I want?

Answer 1

If the hyperref links are not needed, then this use of stackengine will suffice:

\documentclass{article}
\usepackage{stackengine}
\usepackage{hyperref}
\textheight 1.5in
\stackMath
\begin{document}
\[
y \stackon[1.5pt]{=}{\setstackgap{S}{0.5pt}%
  \Shortstack{\footnotemark[1] \footnotemark[2] \footnotemark[3]}} x
\footnotetext[1]{Comment 1}
\footnotetext[2]{Comment 2}
\footnotetext[3]{Comment 3}
\]
\end{document}

As far as a hyperref link, I can get the following code to compile:

\documentclass{article}
\usepackage[usestackEOL]{stackengine}
\usepackage{hyperref}
\textheight 1.5in
\stackMath
\begin{document}
\[
y \stackon[1.5pt]{=}{\Shortstack{\footnote{Comment 1}\\\footnote{Comment 2}}} x
\]
\end{document}

and while hyperlinks appear above the equal sign, they are misnumbered and don't point to any meaningful text at the page bottom.