I tried the demo, but it's actually a tutorial. I got bored and pressed the X. (This happens most of the times. In many sites I had to look for the tutorial and take it later.) In this case, if I close the tutorial the page goes back to the login screen. I'd like to play with the tool for a while, perhaps disable save of close it after 5 minutes or use other restriction.

Fake edit: I can try it! Just one part. Just don't click the X. I still don't like that clicking the X close the whole project. Perhaps add a confirmation.