thanks for the info, good to hear the filament change is on the road. From view of print its a quite basic feature - Marlin has it since 2013 - so quite strange to see most slicers still do not support it in 2016. I believe Mattercontrol with its material management in layer edit is on the right track here, in between a custom Gcode at specific layer should be very easy to implement, will issue that on github.
EDIT: Just have seen in Single print (General settings tab) the pause at layer is already there. Cool.