I don't know if somebody else noticed that, but if you untick "show command bar" in the display options, the "Wait for key press" script doesn't work properly : "continue" link doesn't appear on screen, even if the function itself does work (if you press a key, the script will run as if you had click on the link).
Is it because of the "initinferface" function, which seems to contain both command bar and "continue" link attributes ?

This is the same bug that causes the Gamebook not to be able to use it.
Basically, the 'Continue...' link pops up where the command bar should be. So, if you take away the command bar, the link won't show up.

If you really want to have a 'wait' in that situation, you could just do this:

request (Show, "Command")
wait {
  request (Hide, "Command")
  // Your script
}

Basically, this just shows the command bar long enough for it to show the 'Continue...' link, and then it just goes away.

OK, thank you very much Sora