What you’re doing is perfectly useful and as you have noted the fact the only part of the holster and or firearm is touching bare skin above the beltline if you are not wearing a tee shirt or tuck your outer shirt around the weapon as you have in your demonstration photo. Where it might be challenging is if the holster you do this with has a bit too much give, is compressed by your belt, and complicates a smooth draw. Kydex generally doesn’t have this trouble too often unless the upper lip is allowed to ride below the top of your belt/slacks.
Your idea does a good job of solving one problem; just as long as you’re happy with the change in ability of concealment, or, you get ‘enough’ concealment by dropping the tails of your polo shirt.
Some of the holster manufacturers offer back panel padding materials to make an IWB/OWB (if you hang your hardware just so) a bit softer on your skin and side of the body. I’ve seen these with good saddle leather, sheepwool padding, moleskin or other artificial materials pads, etc.
The worst news I have to share with you; and I’m sorry to say: most of us rarely get through life with even one sidearm with just one holster! Good Hunting!