Well, got it working on Retropie and it looks amazing. One main thing is to make SURE you delete all the .dat files that sirdrak has included in his files. Daphne will recreate those when it runs and those will likely work fine.
As SIRDRAK is busy doing incredible work re-coloring our nostalgic imagery, hoping someone else might take the time to post a note about how they got this working with Retropie Daphne (if at all) for those of us who are now too old to boil water correctly.