For DI engines the limiting factor is the high pressure pump and injector flow rates. Due to ethanol having a lower BTU rating that straight gasoline more fuel is needed to prevent a lean out in WOT conditions. Probably the only way is to data log watching the oxygen sensors for lean conditions with a variety of blends.
I haven't seen any data searching the web for blending with Hyundai/Kia turbo engines. Plenty of info for Audi's, Subi's, Evo's and Ecoboost though....