PTC fuses fatigue after the first few trips, their holding current drops quite a bit. It would be good to trip it say 5 times and then do the test. I wonder about its voltage rating, only telecom PTC's good to high voltage but they are much larger than this one. Think about the holding current+voltage and all the heat generated.
PTC are sometimes used as temperature sensors, the change will depend on how hard they are over driven and what they are designed for.
I doubt a small over current will add much wear to the PTC.
What is the pushbutton switch (pads) for on the backside? CAL mode perhaps.
I would expect it to be a button that is used together with one or two of the front buttons to activate calibration, maybe the REL or RANGE button. As you can tell I did not check it.
My reviews are not about uncovering all the secrets in a multimeter (or any product), this is much better done in a thread here. I am satisfied if I can describe the behaviour of the meter in a way that means people buying it knows what they get.