so the UK being 230v is kind of a lie. we used to be 240 then the whole “universal 230v” thing came in and we officially moved to 230v but in reality nothing actually changed. the grid is almost always closer to 240v. Its within the tolerance so I guess it doesn’t really matter.
In a lot of the EU the same thing happens but its 220v. because they were 220v then “officially moved” to “universal 230v” but didn’t actually change anything.
As long as everyone is within tolerance for grid and for appliance ratings it shouldn’t matter but some devices can be more sensitive than others.
Its worth noting that this has been the case since January 2003! - I do wonder if we will ever actually change to 230 instead of pretending.
now the history lesson is done here’s some actual info on the plug:
Its worth noting that in my experience (I have 4) the LB smart plugs out of the box overread by about 10% on every reading. I plugged it into a shelly plug and put a load on it to get a reading under a stable load to calibrate it. if you are worried about it overreading then it might be worth calibrating if you can.
if your are getting high enough voltage from the grid to damage the plug then you probably have bigger problems to worry about than a damaged plug. If you have 255+ (I think - the threshold changed every now and again) then you can call out a national grid emergency team to investigate. also I suspect a smart meter (if you have one) would get very upset by that point too and trigger something to happen.