An USB isolator allows eradicate floor loops and minimizes electromagnetic interference (EMI) amongst the computer as well as the related gadget. 1x GND 3V3 (P2 with two pins 2.54mm) connector may be used to power externally the WCH CH569 MCU (it is suggested to eliminate the P4/SHUNT in that case https://jaidengdzvr.shivawiki.com/7160152/detailed_notes_on_hydrabus