My jazz runs 100% on bioethanol on warm days (about 3/4 of the year) and 60% in winter.
I've got the engine light on everytime, and I believe it's because the ECU gets crazy because of the mixture, but as soon as I'll fill up the tank with unleaded, it goes away.
Been driving like this for about 8 years now, no issue so far and it's way cheaper on the fuel station
Of course the car is a little bit more of a guzzler under alcohol, and I will do about 500km with a tank!
It used to be very interesting to run on bioethanol a few years back, when it was only 0.20c per liter, but since covid and all the fuel price madness, somehow it went up to 0.70-80c per liter which is crazy...