They are good buttons, but I'm not so sure they will work with 1/2" either.
I use the Seimitsu KN buttons which look to be about the same length. They are in a 1/2" panel, but it's routed out. I don't think I even considered trying it in the full thickness panel. I'm pretty sure it won't work, but I'll check when I get home.
I'd contact focusattack and inquire before ordering.