“Where a demand to change venue claiming the designation of an improper county is opposed by a plaintiff, any subsequent motion to transfer venue must be made within 15 days after service of the demand, in the county designated by plaintiff (CPLR 511[b])”
“Here, after defendants’ demand was opposed by two of the three plaintiffs in these joined actions, defendants improperly noticed their motion in Westchester County.”
I always learned it was just safer bringing a venue changing motion in the Court where the case is brought. The CPLR gives the practitioner the right to bring the motion in the county where venue should have been laid. As can be seen, that is fraught with risks.