My rav holds it is assur to ask someone who “holds of” the brooklyn eruv to carry for you because he holds it is completely passul and therefore no different than asking a non-frum Jew to carry in a place with no eruv at all.
On the other hand, in other places where there are “kosher eruvs”, he recommends being machmir and not carrying but he does allow someone who doesn’t carry to ask someone else to carry for him.
This is a classic case of Chumra vs. Din.
It has been mentioned in this thread that there are those who hold of chalav yisroel as a din rather than chumra. But I believe most people in today’s “yeshivish circles” who “keep cholov yisroel” do so as a chumra and not a din and therefore they can feed it to others. To prove that they are only being machmir, most, if not all, of the cholov yisroel people I know of would be meilkel to feed cholov stam to their kids when out going “out of town”.