Smart Reflex Testing using boundary scan control

I wish to verify the smart reflex circuit by controlling the Vcntl3:0 signals with boundary scan EXTEST instruction then monitoring the smart reflex voltage.

Drive out vcntrl: 0000  Look for lowest smart reflex Voltage.

Drive out vcntrl: 1111  Look for highest smart reflex Voltage.

 I see the compliance pattern requires PORz and RESETFULLz to be high.

Is there any reason this will not work? 

Any other considerations or prerequisites?