I'm wondering whether they have built a routine into the event to punish players who are doing too well, i.e people picking up keys faster than they want. Perhaps this is the reason for the repetitive long term quests.
Someone above has mentioned gathering over 4k keys after 4 days. What have the people picked up who have mentioned the problem?
So far I have 2,200 keys and I feel like I've been going pretty quickly. I've used about 60 or 70 hours of time boosts and I bought the double collect building and I've otherwise completed any quests I can when I can. I haven't seen a single repeated quest to this point. The collect 7 relics quest has been pretty common though.
Maybe it's just because I'm not as far through as all you are, but I don't think I'll need more than 2,000 keys a week anyway.
@Timneh I hear you, but I also feel like people missing out on the Brown Bear may have similar problems to those who missed the Fire Phoenix.