Hi Tim,
I have configured it every which way and have ten different versions saved none of which do what I *think* it used to be capable of which was:
1) Open SEB , at this point you can close SEB if you want to
2) Click start quiz, you can no longer close SEB
3) Finish and submit the quiz and you are able to close SEB again
I am sure that was possible a few years back, perhaps I was imagining things?
The only way I can see of controlling this is by setting passwords or adding close links which is a bit of a pain with multiple tests as you have to regenerate lots of SEB files in order to change the close password.