No idea of the exact policies for all, but can certainly give our recent experiences with a stroller over the past 12 months.
LGW- as per CWS
NCL- Drop at gate, collect at reclaim.
DUB - drop at gate, collect at door.
MCO - drop at gate, collect at reclaim.
LHR - drop at gate, collect half way up airbridge now.
MIA - Drop at gate, collect at aircraft door.
GCM - Drop at gate, collect at door.
VCE- Drop at Gate.
BCN- collect at door.
AGP- drop at gate, collect at reclaim (oversized luggage belt).