That is, indeed, much easier. I imagine it's a "more recent" feature, too, where "recent" could be a long while back. I've been using the method of directly editing the Normal.dot (or dotm, later) file for many decades now. If Word is, for all practical intents and purposes, allowing you to do this as you describe then it is much easier.
You don't really have to worry about saving the original. If you nuke whatever Normal.dotm is in the folder Word will generate another one, and it will be generated with the defaults. Now if your original is already modified in one way, and you're not sure about the tweaks you're making, it makes absolute sense to save the existing Normal.dotm as something like OrigNormal.dotm before going back and making the tweaks. It's really a matter of what your fall back Normal.dotm should be for you.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
The purpose of education is not to validate ignorance but to overcome it.