I have not heard back yet, but will use this thread to report the answer. Now we all know anything is possible with enough time and money, but I'd like to not go too broke.
Response from Genesis when I asked if he knows of anyone running their system with the 5.7 conversion:
Thank you for reaching out. If they are, they haven't told us, but if the conversion doesn't change the location or orientation of the battery or fusebox our system should work fine. If it does encroach into that area and requires any modification at all, the diesel system would be the solution. It puts the battery inside under the back seat.
Mike Heverly