n0> I’m not aware of any Chassidim not using an eiruv because of a chumra.
I did not research this beyond the visuals. I understand that this is a legit halachik difference between the communities (unless you hold that chasidim are illegitimate group of Ashkenazim who changed the minhag), not a chumra. My quote from Sephardim is that they’ll follow Ashkenazi community halakha when it contradicts theirs. Same reasoning they are sporting black hats, blending into the yeshivish community.