One click to apply the master you want to the pages you want.
This is a combo with both versions of this script:
v1: Select the Master Page you want to apply, then a paragraph style (to make apply the master just to pages containing that style) or blank pages, or even pages, or odd pages. You can use a combination of these filters or just one. But you need to choose at least one (or paragraph style, or blank pages, or even pages, or odd pages).
v2: A lot of combinations and possibilities. Choose one or more paragraph style, and/or one or more character style, and/or one or more object style. You can also select blank pages, all pages, odd pages or even pages. For each “filter” you can choose a different Master Page to be applied. And you can also combine styles with page type. Very powerful.