Thanks a lot :P
Well, one thing that will be happening, someday... is a temporary cap when these global bosses are around. And we'll be able to set it wherever we wish.
The main issue with prizes per tier would be the amount of prizes needed. Instead of having 7-10 items total, with 13 tiers, we're easily looking at 50+ items. Some prize shops don't even have that many items. Doing it by tier isn't a likely thing to happen.
It would be very cool if we could have special prizes (same across all tiers, so not a weapon) for the top X performers of each tier though. That gives lower tier pets something "extra" they can aim for.
What would this solve? Wouldn't the top pets just get the top spots because they can do more damage in five hours than the smaller pets can?
Yeah, and with the current system, the top pets can spend a shorter amount of time battling and still get good prizes, while if a smaller pet wants to earn good prizes, they can spend a longer time battling. I'm not saying that it's a perfect system by any means; it's old and broken like most of the BC. I'd be happy to see it changed to something that would work better, but I haven't seen a suggestion that I think would really fix it yet.
Choosing a time is tough because unless we somehow cover a full 24-hour period, we're always going to get complaints that we're favoring a specific time zone (and we'll get some of those anyway based on what time we release the boss).
There are also only two battle admins, and we're both on the east coast of North America. We like to be there for the start and end of a boss fight to make sure everything runs smoothly and adjust the boss if necessary. It's difficult (sometimes impossible) for us to do that if the boss fight is estimated to end at a weird hour for us. The 12-hour system works well because we know we have time to sleep (or go to work or school) while it runs.