I know a laboratory that uses their VNA on an ESD mat. (They pointed it out.)
How much of this is to mitigate real risk, and how much to instill a culture of care is up for debate.
At the end of the day when you're testing filters, amplifiers, or other muti port devices, almost certainly the coaxial outer connection will maintain a common ground so the ESD mat offers limited benefit.
However what I am an advocate of is the psychology aspect: if you engender a culture of care where people think twice before each step rather than go gung ho into everything, that can have significant benefits, particularly in a lab where equipment is shared, and absolutely in a student lab, where stuff inevitably happens.
In later years I've been chastised in some clean rooms, for bringing in paperwork (yes, the paper fibres are a no no in some clean rooms) or a laptop with a fan in it for example. You just don't thnk about that stuff until it's drawn to your attention.