How to set field page numbers to begin as something other than 1?

There should be three ways of inserting page numbering in a header:

  1. As outlined in the guidebook, insert simple page number on a new page style, with the first paragraph having a page break beforehand, with settings adjusted to start page number on user defined value. (This has two critical limitations for me. First, I can’t get it to work where I need it, namely, endnotes. Second, I have additional content in the header, which is why I’ve been using the Fields method instead for page numbering)
  2. Insert page numbering through the fields functionality. (However, I can’t seem to find how to set it to a page number other than the actual page number according to the odt doc, which isn’t what I want. Alternatively, I’ve been trying to set a custom range to match the page numbers I want, so, say, 200-220. I presume it’s possible to this via the Fields>More Fields settings… but I’ve been playing around with it and can’t find the way.
  3. Insert page numbers individually on a page-by-page basis, by having different header content for each page. (But for some reason I can’t seem to apply different header content to more than 3 pages in a given style.

Preferably I’d like to resolve this issue through setting the custom range of the field (2). It just seems easiest that way.
If that doesn’t work, I’d be willing to insert page numbers on a page-by-page basis (3). There aren’t that many pages which I must do this for.
I’d really like to avoid the simple page number insert method as I’ve already formatted my headers without it.

Lol.
1 and 2 are identical. And additional content is not a problem for 1.
3 is natural, because page style is a style, and you have repeating content when you apply the style (it can have different content for first, left, and right pages, but all left pages will be same, and all right pages will be same). The same way, it would be fun to expect that you can apply the same font style to different places, and expect to have it different in different places - unless you do a manual modification, i.e., create an ad-hoc style.

The real problem is endnotes.
What is the specific situation, that requires you to change a normal flow of pages, when you are in endnotes?

1 and 2 are identical.

Ah, so Insert>PageNumber is identical to Insert>Field>PageNumber? If so, I must’ve gotten mixed up when playing around with it. Hard to explain, but perhaps silly of me.

3 is natural, because page style is a style, and you have repeating content when you apply the style (it can have different content for first, left, and right pages, but all left pages will be same, and all right pages will be same). The same way, it would be fun to expect that you can apply the same font style to different places, and expect to have it different in different places - unless you do a manual modification, i.e., create an ad-hoc style.

But shouldn’t I be able to have different header content by deselecting the “same context first/left/right” page box? Otherwise, why should I have the option? And as for your comparison with font style, it’s not the page style I wish to change, but the content. I have lots of different font/paragraph styles, which enable consistency in format with differing content.

The real problem is endnotes.

So you see no way of beginning page numbering for endnotes page style at a value of my choice?

What is the specific situation, that requires you to change a normal flow of pages, when you are in endnotes?

Excuse me, but I can’t answer this. It’s happened many times, between my current ask.libre account and an older one, where I encounter a limitation/bug, exhaust the possibility of overcoming it, so decide to do a workaround. Then when I encounter another limitation or bug to such workaround and seek to overcome it through this site, the responders ask why am I doing this and advise me to do it differently, distracting from my question when I’m 100% sure I can’t do it the way they suggest because of other limitations/problems. (But if you’re merely curious: I’m formatting a book and need to export chapters to PDF individually and compile it all together, all endnotes at the very end, through PDF editor).