rescaling size of content in LibreOffice Impress

Hello, I created a poster (A0 format) and wanted to obtain a smaller version of it (A4).
In my case this was useful to print it and see what the document looks like on paper, but I think that in general there are other reasons why one might want to change format. The same question may apply to LibreOffice Writer as well.
I tried to change the paper format, but if I do this, then the content of the document (text, shapes, etc.) gets messed up. In particular the font size is not reduced or increased accordingly. I know I can export to PDF and print the file thus obtained, but it would be nice if LibreOffice could just (ask to) rescale the content according to the paper format specified.
Do you know if this is currently implemented and hidden somewhere?