Its not a recipe for disaster... i fit them as they are supposed to be fitted, with all the safety precautions in place,
from the element , there is the correct cable, , it plugs in to the correct thermo extention,with trip switch.
If someone is then going to plug it into the mains, ... then the plug socket that they plug in to , should be up to scratch,..... meaning its protected with a trip on the mains or the socket, which is the norm anyway,
a 2kw radiator plugs in to a normal socket, so this should be fine...
the point of power , after fitting is the purchasers responsibility,
all the protection , before it reaches the power scource will be in place.