Geeetech A20M Direct Drive
I decide to use one of my extruder on Geeetech A20M as a direct drive to print flexy and using retraction.
with this adaptor you can use one of your Geeetech A20M original extruder and motor as direct drive and other remain Bowden system.
No support needed

I recommend to use 3 layer walls and 20% Gyroid infill.