Although electrically the IC can support a different voltages between AVIN and PVIN operationally it will not work properly if that difference is too wide.
The ADP2164 doesn't have a level shift circuit between AVIN and PVIN, so signal transfer
between AVIN and PVIN domain will fail if PVIN-AVIN> 0.5V or so.
As long as the controller is not enabled you may be fine but as soon as signals such as gate drive pulses and current sense information need to cross that domain having different voltages between AVIN and PVIN is not recommended.
LucaV