I emailed them and asked as I'm in Sydney and didn't want to mess it up - they said to wait until the end of my workday, so I posted it at roughly 5:30 my time. I hope I didn't spoil it!
In any case, I had it all worked out already. But looking at other people's submissions today showed me that I found some easter eggs other hadn't. That was encouraging. (And I missed some that others found, of course.)
I also realised I'd missed a lot of easter eggs, like the morse code - I wish I'd spotted that!