VCV is home to lots of interesting stuff
VCV is home to lots of interesting stuff... not necessarily a sign of a boneyard!
For example, the superwhale and baby plastic jet were both recently extensively tested there (and the -8 even did a 1,000,000+ lb. MTOGW type record there), ...as well as a lot of "New type" engine testing is done there.
The long obstacle free runway is great (albeit a bit rough in spots), the WX generally reliable, and VCV is adjacent to some great testing airspace and related resources.
As to being up at FL430, that is pretty typical for an FCF (or for a re-fly of a B1 profile) following any significant MX or modifications.