Good day, I actually like your challenge and I believe I've abilities that may help you. Your application has long been submitted. 1x GND 3V3 (P2 with two pins 2.54mm) connector may be used to ability externally the WCH CH569 MCU (it is recommended to get rid of the P4/SHUNT https://hydrabus08531.blogdigy.com/the-definitive-guide-to-hydrabus-49457659