MB4 231a: Eruv Chatzeiros in a Shul and in Two Containers (366:3-5)

Why is the minhag today to keep the eruv food in the shul even though it's not a dwelling place?

The entire eruv has to be placed in one container.

May a community put an eruv chatzerot in each shul in town?

People who are makpid on each other nullify an eruv.