Counting of galaxy triplets in overlapping (extended) patches. We consider a mock footprint that is split into three patches that are extended by a scale, θ_max, over their boundary. We also show three galaxies that each lie in a different patch but that are contained in the intersection of the three extended patches. When computing the 3PCF multipoles in the first patch, the form of Eq. (C.1) only allows us to compute the G_ns at position x₁, meaning that only the depicted triangle is included in the 3PCF. When encountering the same three galaxies in the two other patches, a different reference will be chosen, such that each particular triangle configuration will be counted sixfold across the full footprint.