Does LineageOS & GrapheneOS provides source code for all closed kernel drivers include modems? How many people they can assign for serious Android security aud

Does LineageOS & GrapheneOS provides source code for all closed kernel drivers include modems? How many people they can assign for serious Android security audit (>million lines of code)? So, better be realistic about resources. Lineage even used Google DNS & Google internet checkers a lot of time, and probably uses it now. And I even don't started talking about general Google Play store apps, sending user data to Chinese servers is "normal" now.