I'm running on vSZ 3.2.1 MR1. Maybe that's why the command does not work for you. If I output the help for the command this option is not documented so it's maybe a new option which is not implemented in your branch yet.
However I was not able to verify that the restrictions were removed, because POE injector powered could still mean that the AP is in af mode. I may be able to check in a few week, if the mode has changeds, because the second ethernet port also gets disabled and when I have physical access to the AP I can check that.
I'll also open a ticket, however it would be very nice, if you could report back if you get any updates on this.