We have several custom insight variables that are candidates for creating segments, alone or in combination.
To get all the traffic into the segment, these values would need to be passed in both page view and custom link calls.
In adding the value to custom link calls (previously only passed in a PV), we could still get PV while the instances would increase.
In correlating those values, however, the correlation would now return the higher Instances, not the previous PV.
So we apparently need to choose between the segment and getting PV in a correlation.
Unless you can provide the option to get either PV OR Instances in a correlation.