Yes, this 50% ratio is interesting.
It comes from stats I've had for quite a while, based on around 2500 missions.
If you want another number, here is this one: +2 on the earning ranges every 100 fans.
Another interesting fact: the ego rate has a negative effect on missions longer than 15 minutes, no effect on missions 25-30 minutes and a positive effect (in the same proportions of 2 starbits âr fans) on missions 5, 10 and 15 minutes.
The optimal technique for winnings therefore consists of having an ego rate as close as possible to 0% for long missions. These bring you drunk fans that you bottle. When you attack your series of short missions, release these fans in order to switch to a positive ego rate (you have up to 24% positive rate) and thus further increase your earning ranges.
This is the technique I am trying to implement.