For setting up a Mac, I can't recommend a .osx file highly enough. Dot files in general make setting up a new computer really easy, especially when combined with homebrew's cask. I've been able to setup a familiar dev environment on a new machine in less than 15 min because I've maintained dotfiles. It's a relatively small time investment upfront and the payoff can be massive, especially if anything ever goes wrong on your main machine.
I'm sorry I'm not totally sure I know what you are talking about. Care to link?
Mackup (https://github.com/lra/mackup) is a great tool for this. Beware, however, that it creates symlinks in place of your existing files. So if you decide you don't like it, run the uninstall command before removing the Mackup folder or bad things will happen (I learned from experience).