So by correctly you mean if the case is grounded it should be less than 1 ohm or close to zero? Like that's what you would want ideally?
Correct. That is why the best way to achieve that is with a screw with locking washer into the chassis like this: (green wire)
That upper part of the IEC connector on the Schiit Jotunheim is unused:
The friction fit that we have here is insufficient in my opinion from safety point of view (but good to get rid of buzz/hum). And its path through the PC Board will have insufficient current carrying capability.
To expand, we want the 14 or 20 amp home circuit breaker to pop. These being mechanical devices, in the short term they allow 100 or more amps before they blow. We need the chassis connection to be able to handle such massive amount of current and energy. This is why you want as close of an impedance at zero as you can get. 100 amps at 1 ohm is still 100 volts!!! (Volt = Resistance * Current). We want that let through voltage to be as close to zero as to avoid an electric shock.
I have generated such shorts and it is incredible the amount of power there is. I once cut through a live "Romex" wire that was live. Before the breaker popped, there was an amazing spark and it completely vaporized the cutting portions of the plier! And this is with our weak 120 volt system in US. Make that 240 volts and power delivery doubles yet again.