Article 80 does not apply to a flying display which is private event, although it might have been advertised, as long as those present are there by invitation only. It must not be open to the general public, whether paying or not. This was made clear a zillion posts ago.
Cheers,
Trapper 69
PS - Winco said -
"That being so, I think it would have been more honest of Plemming (and others) to just say 'we would prefer not to have any spectators at the first flight' "
To quote that memorable fictitious Minister - "you may well say that, however I could not possibly comment.....!!!"