Well, a piggyback technically doesn't have to be model specific. There was no custom piggyback for my Elantra but that didn't stop me from using a SAFC-II. There were no pin diagrams from Apexi so I had to do my research using my car's tech manual and then set about cutting ECU wires (scary) and splicing in the piggyback. I also had to add an AFR monitor my trims so I wasn't adjusting blindly.
Basically, all this time and effort was to allow me to tune my air-to-fuel ratio to as close to 13 as possible at wide open throttle. This is the "sweet spot" for making max power in NA applications supposedly. My Elantra was pretty quick - with full header back exhaust, intake, plug wires, lightweight wheels, lowered, tune etc. I was able to get under 7 seconds 0-60 and hold my own against GTIs (my benchmark I guess?

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The downside is that a tune like this is only use at WOT. Any partial throttle inputs would've been overridden by the ECU's short term fuel trims. However, in open loop wide open throttle the ECU isn't getting inputs from the O2 sensors to correct fuel amounts.
Moral of the story: There are no simple plug and play piggybacks for the Genesis. Yes, you could probably use something universal but it's going to be a painstaking process that may or may not work/destroy your GDI engine which is already running at a higher compression ratio than the equivalent MPI engine.