I have a 2 color model, where all the Dual Color is at the base 2mm

So using the Dual Extruder Wizard, I can get it to print

as its Black and Yellow I got to use a large prime pillar to empty the head out,

the result is a Huge Black Prime pillar, where really only the bottom 2 MM is needed for the Prime, result the Prime Pillar uses more filament than the whole model

so I beleive using the Variable Settings Wizard is the go, to cull the prime pillar at height x

However this seems not possible once the 2 processes have been grouped by the Dual Wizard

"Must be ungrouped" message

Accordingly this is possible... can Someone please give me a clue how, thanks