There are some individuals at YouTube making videos about of how they crashing down multimeter by applying to them up to 13,000 Volts in their inputs.
Generally speaking all meters them are build according a choice of their vendor regarding specifications and high voltage tolerances.
Regarding bombarding or blast any meter with impulse transient's, this should be made at least by following the rules of the game.
Lets have a look at CAT specifications, so all of us to refresh our memory.
CAT II 600V 4000V peak impulse transient 12 Ohm source
CAT II 1000V 6000V peak impulse transient 12 Ohm source
CAT III 600V 6000V peak impulse transient 2 Ohm source
CAT III 1000V 8000V peak impulse transient 2 Ohm source
CAT IV 600V 8000V peak impulse transient 2 Ohm source
CAT IV 1000V 12000V peak impulse transient 2 Ohm source
Regarding input over-voltage protection...
The limit here this is the max voltage that a meter this is specified that it can measure.
Therefore any damage to internal components when a meter this gets connected to above 1000V source, this is justified and expected.
In conclusion
Peak impulse transient tests them are made so a multimeter to shown safe for the operator of the meter by it getting burned with out causing harm (electrocution) at the person using it.
Therefore such a crashing down of multimeter's by injecting enormous quantity of high voltage, this has nothing to do as testing process, so this to presented as indicator related to internal electronics part quality level of any multimeter.
What people should look about at handheld meter, those are: Accuracy, Measuring speed, safety, a robust case, and needed features.