is that POINT SHOOTING with the off hand is not that difficult to do with some practice.
Basic 2 handed ISO-type stance with the handgun fully extended on body centerline between the chin and nose. BOTH EYES on target and looking just above the handgun at point of impact.
The switch to strong side one arm only takes only a short time to get to be almost as accurate and fast -- keep the extended arm MID BODY LINE about mouth level. Recoil management becomes more of an issue with one hand.
The switch to weak side is still slower but very managable with practice. Sight aligned shooting from the weak side was difficult for me ... except when using the recently purchased laser
which is an effective way to cheat.