I have long promoted keeping a holster for your carry gun that is for the opposite hand. In the event that you sustain an injury to your dominant hand, or in the event of having surgery on your dominant side elbow, shoulder, wrist, etc…, you will be out of commission for a recovery period and you will need to carry your gun on the opposite side, accessible to the other hand.
Beyond this, however, you should also have an appropriate holster for a different carry mode, essentially, a different location on your body. I believe all concealed carriers should have a secondary carry mode, as this suits the case when a backup gun is carried, if ever. Beyond this, however, you may need to switch to a different carry mode due to injury.
Case in point, I carry AIWB and recently had an injury in my abdomen, directly below where the butt of the gun presses. It was simply too painful to carry my gun in the usual location for a while. Therefore, even though I typically do not prefer it, I switched to pocket and ankle carry for the time being until I healed up.
Unless you are the terminator robot, you are likely to sustain injury at certain points in life, and you will need to switch your gun to the opposite hand, or to another body location, to accommodate a recovery period. Be prepared to do so before the need arises.
Reflex Handgun 