Work place toilet is using one of their sink tap, Twyford. Interesting, unlike the typical tap, it allows horizontal movement but not vertical. This allows the user to have simply two configurations

[1] Weak cold water
[2] Strong hot water

This is clearly a two degree freedom problem, and squashing it to one degree freedom simply isn’t the right engineering. One simply can not reduce the complexity of a system simpler then how it should be.