The major contradictions have to do with labor bureaucracies that emerge as a function of organizing labor within a system that down to its very core exploits labor. Unions are not revolutionary formations which seek to abolish the class based caste system of capitalism. Some of the things that a union might do for their members might be bad for the class in general, as it privileges workers in the union without necessarily showing class solidarity. As a rule if thumb, I think: what is good for the union isn’t necessarily good for the working class, but what is bad for the union is always bad for the working class. You can be in a union and be a communist, honestly i think this obsession with having the perfect line on every issue is a kind of defeatism (this isn’t a criticism, just an aside, don’t mind me).
I don’t know anything about that, I have an acquaintence who also uses GrapheneOS and has helped me get it set up