I would like to have the control block 2 blocks above the elevator platform (so that it's at eye height). Would that change be possible. It could be a config option (off by default) or even an option on the control block.

Sounds good to me.

In the next update I am adding a display block to go on top of the elevator block.
The display will have buttons with the floor names.
Because of this I won't change the controller offset.