Yeah, you can use Test. Since he was alive at the time when your BTB started, therefore causing another dimmension. This happened with Evil Austin, I think his name is now, awhile back. He wanted to use Benoit, and the mod's let him because he altered real life in his BTB. So for an example, lets say, in Dylans fictional real life, Test moved to Texas due to an easier way of managing his schedule with WWE. Altering real life, because in real life Test lived in Tampa, FL. I doubt you get me, but in a nut shell, I'm saying its ok to use him.
I try to stray away from using deceased wrestlers though. As much as I want to, I prevent myself. I get a creepy, and eeire vibe from it. Strange, and odd I know, but whatever. I'm currently using Benoit, and Gurrero in a What If installment, and I only made an exception for them due to them being amazing wrestlers.