<<You'll have to take my word for that because I am not going to name the venue.>>
Why on earth not? It might help people to explain things to you.
I fell about at your mention of 20 seconds roll then up to FL400!!! Apart from jet fighters and the odd clockwork mice bizjets I think I've only seen one commercial aircraft get airborne in 20 seconds and that was a Dash 7. In busy airspace not too many aircraft "launch up to FL400".