While there isn't an official paper titled "Ultimate v6.0," the research community often refers to the "R" (Revisited/Revised) version or subsequent massive multitask updates as the "Ultimate" iteration of the benchmark. The benchmark is currently in a state that encompasses the datasets found in the "R" update.
In the world of custom cars or PC hardware, "Xtreme Ultimate" is a common naming convention for over-the-top, custom-built projects. xtreme ultimate v6.0