Probably enough where if the credit prize was only 50%-60% of the free spin EV, then always picking the credit prize would drop the EV of the machine to below 75%. And with the Konami games, this would make a huge difference, the bonus is a MAJOR part of the return. Konamis slots such as Adorned Peacock, China Shores, and Astronomical. I would think a few jurisdictions (NJ for example) would legally need to point out which option gave the better return in a help screen at least. Fan-favorite Online Slots by Konami Gaming Rolling Out on Caesars Sportsbook & Casino. I would agree they should be equal EV or at least close, 50% to 60% is pretty nuts. People like to quit after finishing free spin bonuses as well. That might be the logic, but I'm not sure how sound it is. I did advocate for the instant win prize to be raised closer to the expected return of the free spins. The players that take the free spins are more likely enjoying the game and will probably continue playing.
No, I never heard an explanation but I would speculate that the many of people who are taking the instant win are more likely to cash out because they have a 'big' win.