Hi, Yes we have tried .
When we used the external battery the reading distance was better. You have to a little bit modify input impedance of antenna as chip input impedance is not the some in passive and BAP mode. The reading distance in free air in BAP mode 2W/ERP was about 25m all depend on antenna design and impedance matching.
One important note, the input impedance of chip is variable and depend on power that is comming on input of chip.
