Would you say it is okay for someone who, like most, holds with the Psak of Rav Moshe and most contemporary poskim regarding an Eruv in NYC being assur and chillul Shabbos to carry, to give someone a package on Shabbos to carry within the Flatbush or Boro Park Eruv since the Flatbush and Boro Park Eruvs has on whom to rely?
It depends whether you hold the other shittah is reliable.