This answers the unwrap part

This answers the unwrap part

Overview

| M-x package-initialize  <return>        | package-initialize        |
| C-x C-x C-f test.tex  <return>          | find-file                 |
| M-x display-line-numbers-mode  <return> | display-line-numbers-mode |
| M-g M-g 27  <return>                    | goto-line                 |
| C-2  C-c .                              | LaTeX-mark-environment    |
| C-u C-x r s a                           | copy-to-register  ?a      |
| C-<up>                                  | backward-paragraph        |
| C-SPC                                   | set-mark-command          |
| C-<down>                                | forward-paragraph         |
| C-w                                     | kill-region               |
| C-x r i a                               | insert-register   ?a      |

Detailed Answer

This answers the unwrap part

1. Copy the below snippet to test.tex.

\documentclass[handout]{beamer}

\begin{document}

\begin{frame}
  
  \frametitle{Foo}
  
  \begin{block}{First Block}<+->
    Foo bar.
  \end{block}
  
  \begin{block}{Second Block}<+->
    Foo bar.
  \end{block}
  
\end{frame}

\makeatletter
\gdef\beamer@currentmode{beamer}
\makeatother
\begin{frame}
  
  \frametitle{Bar}
  
  \begin{block}{First Block}<+->
    Foo \uncover<+->{bar.}
  \end{block}
  
  \begin{block}{Second Block}<+->
    Spam \uncover<+->{eggs.}
  \end{block}
  
\end{frame}
\makeatletter
\gdef\beamer@currentmode{handout}
\makeatother

\end{document}

2. emacs -Q
3. M-x package-initialize
4. C-x b *scratch*. Copy the below snippet and do M-x eval-buffer RET.

(defalias 'unwrap
  (kmacro "C-u C-x r s a C-<up> C-SPC C-<down> C-w <return> C-x r i a C-x C-s"))

4. C-x C-f test.tex RET.
5. M-x display-line-numbers-mode
6. M-g M-g 13
7. C-2 C-c .
8. M-x unwrap RET
9. Profit

This answers the unwrap part

1. Copy the below snippet to test.tex.

\documentclass[handout]{beamer}

\begin{document}

\begin{frame}
  
  \frametitle{Foo}
  
  \begin{block}{First Block}<+->
    Foo bar.
  \end{block}
  
  \begin{block}{Second Block}<+->
    Foo bar.
  \end{block}
  
\end{frame}

\makeatletter
\gdef\beamer@currentmode{beamer}
\makeatother
\begin{frame}
  
  \frametitle{Bar}
  
  \begin{block}{First Block}<+->
    Foo \uncover<+->{bar.}
  \end{block}
  
  \begin{block}{Second Block}<+->
    Spam \uncover<+->{eggs.}
  \end{block}
  
\end{frame}
\makeatletter
\gdef\beamer@currentmode{handout}
\makeatother

\end{document}

2. emacs -Q
3. M-x package-initialize
4. C-x b *scratch*. Copy the below snippet and do M-x eval-buffer RET.

(defalias 'unwrap
   (kmacro "C-u C-x r s a C-<up> C-SPC C-<down> C-w C-x r i a"))

4. C-x C-f test.tex RET.
5. M-x display-line-numbers-mode
6. M-g M-g 27
7. C-2 C-c .
8. M-x unwrap RET
9. Profit