Floating tap holder

Does anyone have an experience using a floating tap holder on the 15L ? Rigid tapping is not working for the thread I require (M12 X 0.5) with the thread being oversize each time. I’ve got the holder dialed in to around 0.01mm in each direction so i think its simply beyond the capability of the machine hence looking at a floating holder.

@Paul_Prescott how oversized are you seeing your threads come out with rigid tapping? I would think a floating holder would really only help is in the Z direction, not with X (concentricity with the part).