63 Keyboard Switch Tester with labeled keycaps $50. ... The keyboard switches are in the layout of 9 x 7 and feature DSA keycaps mounted in an acrylic base measuring 18.3 x 14.7 x 2.5 cm.

This would let you change your layout and label macros on the fly. And it’s exactly the premise behind the PolyKybd , a mechanical keyboard with OLED displays inside each key.

It included a special "Keyboard" button that would swap the layout between QWERTY and Dvorak logically, but the physical keycaps would need to be re-arranged to match if you needed a label reference.