1. I was using Storyboard v4.2, but recently updated to v5.0. Same behavior in both versions.
2. Yes these controls were cloned before by gre.clone_control("original", "clone", "target_layer", control_data)
When I then try to gre.delete_control("clone") nothing happens on the screen, even though the control is internally removed.
3. I tested the behavior in a minimalist example myself and I was unable to reproduce the issue at first. Further digging showed that this only occurs when the original control is located on another screen than the clone. I will attach a small example application showing the failure case.
4. No scrolling layer - just a standard fullscreen layer
In the example the keyboard key presses for c, d, and r are handled:
c - clone control
d - delete clone
r - redraw