Read-only Persistence?

[HereIAmNow]

You could just backup the persistence file when it has your desired settings in place, then just restore it after further use, thus discarding any posterior changes.

That's not going to work, because it needs to not write in the first place, to save on wear and tear on the drive, and I don't know of a secure way to back it up in this case, so I'm now trying to edit the ISO file to make it run in a live mode which is augmented from the original, but without persistence.