|When converting I was using my map switcher setups but with COVID and the whole chip shortage, my manufacturer stopped offering it. The other option is to use the Nistune board itself.
If it has a factory fuel pump we will need to upgrade it and bypass the fuel pump controller.
No down sides running E85, but if dual I do recommend changing the fuel filter yearly and running a tank of 91 octane every few months.
If you want to run straight E85 then no need to worry about sourcing a Nistune board. To run 91 you could just swap the chip if needed. I do have guys who run E85 and never run 91 octane and these cars are doing just fine.