Sure. Why is that hand under there? What does that hand do to help your pistol hand? I dunno. Give me a reason to do this when the support hand can be of more help not there.
I am not going to get into a whole tactical thing. But I have worked 2 man covered movements in confined spaces and worked stacked on a team. Pistols are out and ready for a reason. This is definitely not of no need for those dynamic movements.
2 cops nonchalantly drawn walking through a house, that support hand is best used for other things, maybe to parry someone coming out a door, to move something, grab, use radio, flashlight, etc... You can hold that pistol the same way without that support hand under there.
Sometimes people get muzzled in dynamic situations. That's why we practice finger off the trigger until we shoot.
