Hi, Manuparis
I do it manually during printing.
1. Install DUPLICATE extension from Marketplace.
2. Duplicate Extruder 1 to Extruder 2.
3. Slice
4. Preview. A slider appears on rh side.
5. Slide up and down and read the layer you want.
6. Start printing and see Z layer on the screen.
7. At the chosen layer, press once, Mixer, Toggle Mix.