Real talk about the log in rewards. the only useful reward is the 1 gem, and waiting 10 days to get it if you’re stuck on campaigns can be devastating. The only way to move forward may be to get more monsters and the only way to do that is events or daily login.
Getting 1 summon every 50 days passively is far to long. I propose you make day 9 or 10 give 2 gems; at the least 1. That way you could summon at least every 20 days passively, or every 10 days with a 3 trial clear.
Fruit are not a good incentive, especially after that fruit event. I would consider modifying the friend bonus to have an optional gem with a much higher cost instead of just a fruit if you wanted.
As many have said, after hitting 100 there is no reason to log in sometimes during down time. Giving better incentives will give both lower and higher level people more of a rewarding reason to actively play.