There is so much wrong with this post that I don’t even know where to begin.
Let’s start with:
From the very first line in the first post of this thread:
You do understand what the word “also” means, right?
As the title beside his/her name clearly states, the user is a tester for the Dev ISO - the development version of what will be the next ISO that is released. The user may or may not be using the testing ISO for his/her main system. That is immaterial.
Perhaps you are not aware of what the next ISO will have included?