Ran the util, and I heard audio, but nothing moved for the first 5 seconds. Then all of a sudden the colors got all messed up and slowly faded back to regular colors.
You don't need a separate branch for vertical. You simply need a vertical setting and you can rotate all your artwork on axis and adjust for it. Your aspect ratios would then be 9:16 , 10:16, or 3:4. Automatic detection might not work 100% of the time because I've seen setups where windows was still in landscape but the FE/Emus were set to run in portrait.
You might want to look into ffmpeg as that's the only thing that works well. I helped Emb do a lot of testing in this area on RetroFE and everything else had issues. Although I don't think he was trying Direct anything because of cross-platform support.
Launching worked finally but you aren't sending the right path to your exe, forgot a backslash and the CLI switches.
RadKade log:
8:22:40 PM: Sending arguments: "Nintendo Entertainment System" "10-Yard Fight (USA, Europe)" "RadKade" "D:\RadKadeRadKade.exe"
HL log:
20:22:41:523 | HL | DEBUG1 | +0 | Main - Raw CLI received: "Nintendo Entertainment System 10-Yard Fight (USA, Europe) RadKade D:\RadKadeRadKade.exe"
Should be:
-s "Nintendo Entertainment System" -r "10-Yard Fight (USA, Europe)" -p RadKade -f "D:\RadKadeRadKade.exe"
Don't know if you care but your title name is Rad Kade, not RadKade.
Stretching worked good and artwork stayed as the correct ratio.