First of all, please be nicer to the other people in this forum. They're all members of the community who are helping you on their spare time. (Not me, I'm an employee.)
The preference to disable signing enforcement should work on the unbranded builds. However, I don't know if it works in the way you seem to be testing. I think you mentioned dropping the files in a global location, instead of using the regular installation method from the Add-ons Manager.
The unbranded builds are intentionally branded as Nightly. The version number you see in the About window is what should matter.
Additionally, if all you want is to try out a version before listing, you can upload unlisted versions the are signed automatically. See this blog post for details.