Different language keyboards are on different version numbers. Whenever a country adds a new character, their keyboard firmware gets a version upgrade. US, UK and International EN are all different keyboards.
My guess (because you never see those version numbers on packaging) is that 1.4.6 is the keyboard without Touch ID and 1.6.0 is the version with Touch ID...
My guess (because you never see those version numbers on packaging) is that 1.4.6 is the keyboard without Touch ID and 1.6.0 is the version with Touch ID...
Turns out it's the other way round. 1.4.6 is the one WITH Touch ID and 1.6.0 is the version without.
I was expecting it to be the same way you guessed.