Unfortunately there are not much options available for the prime pillar.
Simple and more intelligent features could improve the dual print process dramatically.
1. Exit prime pillar if last layers are printed only with one color. There is no need to proceed with printing the prime pillar if last layers are only one color. See screenshot attached.
2. Option to define how the prime pillar is printed in layers with only one color: a) print with both extruder b) print only with active extruder
3. There should be option to force the extruder printing the prime pillar always before the object. Start with prime pillar after layer change.