Is there an overlay specification for \frame<...>{ that yields the last version of the frame if the frame is built with relative overlays?
The handout version achieves this, but sets it globally. I'm looking for a frame-specific solution. I think it works (not elegantly) with \frame<N>{ for some sufficiently large N.
Not sure what you mean by overlay (\pause, \only, \uncover, ...), but it is possible to modify the behaviour of the command before a specific frame, and restore it right after. For instance:
\documentclass{beamer}
\begin{document}
\begin{frame}{frame1}
First sentence
\pause
Second one
\pause
etc...
\end{frame}
\let\savepausebehaviour=\pause
\def\pause{}
\begin{frame}{frame2}
First sentence
\pause
Second one
\pause
etc...
\end{frame}
\let\pause=\savepausebehaviour
\begin{frame}{frame3}
First sentence
\pause
Second one
\pause
etc...
\end{frame}
\end{document}
Frames 1 and 3 use the default behaviour of pause, while frame 2 behaves like there is no \pause.
<3-5,8> on say \items then I can freeze my frame at a given overlay counter. For relative overlay specifications there is a similar hidden counter that increments by + or \pause. With \frame<N> I can still freeze my frame (or replay it with \againframe<N>{label}). Is there a direct way of getting the last counter for a frame? Note that I might also have a <+> element that is not on the last version of my frame. So just disabling the \pause does not answer my question.
\frameis only provided for compatibility with old documents, it was superseeded by\begin{frame} <content> \end{frame}, see section 8.1 footnote 1 of thebeameruserguide