I know I`m late to the party but here in Canada the Flo ones are very popular for work offices. Don`t know if they are available in the US.
https://flo.ca/business/workplaces
We have a very hard climate and they are designed to be used in public places with abuse. Their At Home line is also...
Lets look at the protocol:
https://en.wikipedia.org/wiki/SAE_J1772
That wire is the Control Pilot wire. The EVSE sends the information on the available current with a square wave. The "speed" of the wave is the power available. The diode does not have any effect on that.
Now the diode has 2...
Ask an electrician to add a meter just before your wallplug. It will monitor only you and you can pay back the electricity to the building manager once a year.
That one cost about 120$ (Centron Itron CL-200) but is for 240 volts. I`d say 1hre of work if sufficient.
Something else I`ve seen if...