Iím okay with safety, but not paranoid hyperbole. The problem I have with the CAT IV classification is that it not only includes utility and line side service entrance conductors, regardless of their voltage rating, but also generically includes feeders and branch circuits, as well as all conductors, simply because they are located outside a building. The main concern is supposedly regarding lightning strikes and induced voltage transients.
So, something like a 35-foot long, 120V/20A underground UF branch circuit to a tool shed is also CAT IV.
A 75-foot long 240V/20A underground UF branch circuit to a submersible well pump is CAT IV.
A 120/240 60A overhead feeder to an unattached resi garage is CAT IV.
IMO, requiring someone to incur added expense to upgrade from a perfectly good CAT III 1000V meter to a CAT IV 600V or 1000V meter simply to test and troubleshoot this type of wiring is absurd.
This article from Fluke hits on the examples I mentioned.Meter Safety