[googlerx]

Every elevator in Korea works this way. Pressing once selects, pressing again deselects.

[robocat]

Perhaps you could answer the two questions here, preferably relating to a named elevator model: https://news.ycombinator.com/item?id=32005810

And maybe answer my question too: how do blind people know if they are selecting or deselecting?

Watching foreign button-mashers must be amusing!