I haven't received them yet, but I ordered these a bit ago. Still not in stock so hopefully they ship soon!
EDIT: ... hrm, can't post links yet ... dang. Well, if you go to Motosport, search "TechSpec Snake Skin Tank Grip Pads" and select the 2019 CB500F you'll see they have an image of it with the grip right where are speaking of.
Again, can't comment on how well they stick, but it looks like they are designed for that particular part of the bike (right below the tank). I found the same issue when leaning, I don't really lean-like-a-racer so my knee basically stays where it's at, but I'd like a little more grip on the sides.