Good question!
TL;DR: that is a concern. I don't think it's a big deal, but only real life testing will be sure
Let's get into the weeds!
So the HM is mounted to the sides of the circle by the corners, which come up to the white layer (so 4 layers thick). I tried making the actual HM come up to the top black layer (6 layers thick), and that was strong as hell. It disappears on just about any background, though. I suspect that white would show up better, but not much. The teal shows up really well on almost any background, but the letters are really flexible. It would super be a concern, but they are protected by that circle around them. Really the only thing that is a concern is something that would damage the rest of the card (e.g., being bent in a pocket). For what it's worth, it's the same problem the last design had, but the cutouts are actually stronger since it's not coming to the fine points of the M.
Of course, we're sending these out into the world to be printed on any color combination imaginable, so all of this likely becomes moot in real world situations. Hopefully they always get printed with enough of a contrast that the little pop of color in the QR code makes the thinness worth it 
