I would agree with Gene. If the add-ons come from the community site, they should be safe to use anywhere. Security is one of the tests they have to pass to get there.
That said, not all add-ons work in all versions of Windows. I don't know of any that will actually impede access to an earlier version of Windows, but the add-ons themselves might not always work.
Windows 10 App Essentials comes to mind, as one that only does certain things depending on the version of Windows, and the version of the add-on. And on Win 7 or 8 it won't do anything.
I would suggest creating the portable, and then pruning out any add-ons you don't think you'll need, or that are not community site add-ons.