So I managed to accidentally get a 3h 'free' start on Deep Sea.
I had entered the event earlier today and boosted my ads etc up, but not clicked to collect anything.
I believe that you are only assigned a division once you collect your first points (not when you enter, or watch and boosts).
When I re-opened it I started tapping to collect things. I had not yet had the double ad prompt, and wasn't expecting it (as I hadn't collected anything).
Anyway, after about 10-30s it appeared. But I had offline production to collect / get ad boosted.
I understand that in reality this doesn't affect much and I may have been assigned the same division I would have been 3 hours ago. But still allows me to 'pre-load my earnings for my division (if how I believe division allocation works).
I believe that it looked at the amount I had after collecting for the 10-30s, rather than what I had at the point when I shut it down 3h ago, and could be significantly abused if e.g. I had done this more like 3 days ago, rather than 3 hours ago.
If relevant I first collected with about 5h20m to go, and am in div #247. And Android v 34_86.