The Type Specialization Structure was not officially released. Apparently there were a few bugs and/or missing functionality they wanted before making it widely available.
I made a really simple right-click plugin which should allow you to replace a Diagram/Conditional Disable Structure with the Type Specialization Structure. If you add the attached .llb to <LabVIEW 2017>\resource\plugins\PopupMenus\edit time panel and diagram the option should show up right below the options to replace with conditinal/diagram disable structure.
I believe the issue R&D found with the structure was in developing for it, and I heard someone else mention how it doesn't always work with classes like you'd expect. I'd often find that when developing code, a type wouldn't always do what it needed to, and I'd need to force a recompile, or delete things and rewire to get the VIM to do what I wanted. But after it was good and working the structure never gave me any stability issues.
That and I think something was mentioned about it might not work as expected with classes at the moment. This and the lack of documentation is a good reason to avoid using it, but if you do use it, it sounds stable. I mean NI themselves are using it so the technology itself likely isn't the problem, but edge cases where it might not work right, or might be difficult in getting the compiler to do what you want. When it is official (2018 maybe?) we will likely see it on the palette, and Jacobson's tool shouldn't be needed.