Inverting the signs of the output scalings in the wingwing.main.mix file and rebuilding the firmware corrected the roll backward behavior in stabilized mode. Thanks!
O: -10000 -10000 0 -10000 10000
@Al_B , @rollys Here it is : https://ufile.io/5nf50 I used 1.8.0, not the rc0, that was a mistake.@Al_B In my version, I didn't invert the output but just the roll axis, but good to hear that it works now!