Is there a way to change page sizes in a document with different page styles all at once?

I like what I did with a custom style (6x9) but would like to see the same document in A4 as well. I made the 6x9 document with a lot of different page styles. (It helped me keep track of what went where.) Is there any way to change them all at once? I downloaded the template changer add on, but am not finding it helps. Ideally, I would like to keep my chapter headings in the same page order and just increase the page size.

I can change the page styles manually, but this takes time.

(I realise one way is to change the entire document to default and body text and begin formatting again, but I would like to keep the formatting I have done if I can.)

Edited to say the comment below shows it is not possible but it might be possible to create a macro which would achieve this. I do not have the knowledge or skills to do so but knowing I need to change my page styles manually means I am not doing so wondering if for now, there is a better way.

TL;DR: it’s not possible using LibreOffice built-in tools. You might create a macro for that.

Full version: What you are asking is normally achieved using style inheritance. Several style types, like paragraph styles and character styles, support inheritance (you may select a “parent” style in a style’s “Inherit from:” field on Organizer tab). Then, all properties of parent style which are not explicitly edited in child style would follow the parent’s settings, and changing a parent style’s setting would automatically propagate the change to all children (again, except those children that override the setting explicitly).

But unfortunately, page styles don’t support inheritance in LibreOffice yet (tdf#41316), and each page style defines all its settings itself. So each of them needs to be edited individually in case when some change should be done on multiple styles.

Than you. I now know I need to change the page styles manually and that I am not doing that when a better way exists. I don’t think I am advanced enough to create a macro but perhaps somebody will be. It seems a useful thing to be able to do.

Can you not use MASTER DOCUMENTS to simulate this behaviour? Then changing the master document PAGE STYLE or STYLES could overwrite the settings in one or multiple documents. For example, when changing a draft page size, say A4 to the printed version A5. I know this was not the original use of Master Documents, but I find they can be useful.

Chapter 16 of the Writer Guide contains useful information on this topic. Writer Guides | LibreOffice Documentation - Your documentation for LibreOffice