Rewriting CheckPBCInterfaceOverlapping(). It remains to know why the pbc nodes (H=0.5) overlapping the master/slave were also counted as master/slave, instead of being computed as interface nodes only.
Adapting logic of setInterfaceGeoPBCNew(). Anjos reminded that the curvature will be calculated - although half of it - at each tip node, even though only one neighbour point is included in neighbourLinePoint. This is incorrect, at first glance, but can be corrected through the pbc algorithm, when fint(IR) is summed to fint(IL), recovering the total capillary pressure charged in a unique node. Furthermore, a special method to apply PBC to fint, Mrho, two-phase objects, etc. must be created before evaluation at unCoupled().