I am left handed. Of course it matters! I’ve spent a ton of time customizing my gear! Maybe it won’t matter to you but it sure does to me! Try everything the “normal” way first, but there are lots of ways to customize...
I wear my air integrated hosed console and my backup watch computer on my right, because I want my left hand free to operate my inflator or to vent my wing on the left rear (favorite dump valve), while simultaneously looking at my computer for depth or ascent rate. I don’t understand why anyone would want those both on the same side, it makes no sense, yet it is standard.
I also like my left hand free to direct a dive light, or to make a hand signal, or to pick something up, or to use a knife or shears, or to do any number of things one might do with their dominant hand.
I wear my cutting implements on the right as I reach across to get them with my left hand, shears at waist near center ( so both hands can get), folding sailor’s rigging knife bungeed on web belt near right shoulder above D ring where console clips off.
I dremel cut a slot for a crotch strap on my James Bond era vintage orange colored “White Stag” brand plastic backpack plate, which snugs around my small torso better than any steel plate I’ve ever seen would, except possibly for a small Freedom plate.
My continuous web belt harness, to which I added small trim pockets for integrated weights, has a buckle mounted for left hand release.
To top it all off, despite reading numerous arguments against it, I love my trim, conveniently located Air2, which is attached to a wing. I did add a bungee loop from mouthpiece to left harness strap to keep it tucked, but a quick pull releases it. It feels great to have that Air2 right there so easily accessible to my left hand. Maybe it is right handers that dislike it so much? Practice taught me it is more comfortable to breathe off if I release the velcro loop at the left shoulder.
The frequently recommended option of another hose on the right with a reg bungeed around my neck does not appeal. I already have two hoses on the right, and one goes around my neck. I don’t want anything else on my neck. You see for air sharing I have changed my original short primary hose to a five foot hose that goes under my right arm, across the chest, and around behind the head to come to my mouth from the right, and this I would right hand deploy as is standard with a long hose.
I always explain my gear to a new buddy, if I have a buddy ;-)