Been working on other projects, even ones dependent on this board :). Anyway, I finally made one correctly after an additional issue with updating copper pours. The new design should support full current quite well and tests out OK. There is one 'smart' charger that shuts down after 30 seconds or so, but other power banks seem to work with it quite well without control logic. I need to figure out what is triggering the shutdown, hopefully nothing architectural. The design should just work with or without i2c management.