so does the dc EGC get 'inverted'?"Functionally grounded" is a term that originated in the 2017 NEC, that essentially made most systems fit this term. Even systems that were previously distinguished as grounded and ungrounded, both get considered functionally grounded from 2017 and later. It ultimately means that there is an indirect reference of the DC side of the system to ground.
or does it pass right on through?