Custom master page in Impress

When I create a presentation from outline via LibreOffice Writer I can only choose the Master Pages already included with LibreOffice. How can I create a custom master page and also have that show up in the list of available master pages?

I know I can create a master page, save it as template and create new presentation from that template. But that doesn’t help when I want to create a presentation automatically from an outline.

Bumping this.

@carestad, please bump with votes, not empty answers

@westis - As far as I understand your question, I would create a template according to my needs (background, formats, etc) and start working on my outline after opening this very template.