Brought Happy Hacking Keyboard Pro2 (lang:en model) and put it on MacBook Pro.
We need to automatically disable/enable an internal keyboard of MacBook Pro because this keyboard is pressed key unexpectedly during putting HKKB on Mac.
By using ControlPlane.app which can monitors and handles an keyboard input event, set all of the internal keyboard events to disable if HHKB is connected. It seems to be fine.