It seems likely that the sort of thing you would put on such a key would be better served by either a spot on a tool bar preferably with an actual textual label not a cute icon or a physical button .

The former is visible without looking down at your hands the latter is easy to press. I believe this combines the worst of both worlds.

I don't know how to address your last sentence it sounds clever but it means virtually nothing. If apple does it first its a knockoff if someone else does it first its a rough prototype of something apple will ultimately do better. Heads I win tails you lose?