Tried it, and the setup printed like hell and shifted all over the place. While it didn't chafe, it was annoying having it in a different location every quarter mile. I've had much better luck with a 5.11 waist pack. Laugh if you want, but under a "size up" t shirt (I normally wear large, size up to XL) it conceals surprisingly well*, stays in place, and is a vast improvement in both retention and access.
* I wouldn't pick this for a "go-to" concealed setup, but for most outdoor interactions (say a 30-to-60-second conversation on the side of the road), most folks would have no idea the pack is even there. Plus, anyone who DOES see it... a) it's under a tshirt with none of the logo or pull tabs showing and b) many have no idea what they're looking at. I bought it not giving a **** about concealment, but it's been a pleasant surprise.