After 6 full hours wrestling with compiling it (a Linux native, I am not) and pending Uni work due, you'll have to settle for a teaser for now, since I do not yet have my Gamecube modded and probably won't have time to do so today. So the following screenshots are from Swiss running on a Wii with component cables into a Sony CRT (so you can see those nice scanlines).
It worked pretty much flawlessly from what I saw, aside from existing Swiss problems (assuming I have a 480p display when I have component cables plugged in; Zelda Collector's Edition only having its main menu forced into a video mode). I just tried some game collections made up of originally 240p games, and a couple other Gamecube titles to see how things looked, and it all seemed fine. Like I said, Gameboy Player testing will have to wait until at least tonight or tomorrow.
The usual caveats apply that it looks much better in person, and my phone camera + taking a picture of a CRT + not ideal lighting in the room makes it look worse than it really does. Fantastic job Extrems, since it looks wonderful and doesn't seem to have problems! A huge thanks to you for taking the time to implement this.
I also tested on a 480p plasma, and everything worked fine there too. It obviously didn't look as good, but there were no problems. If I had Gamecube component cables I'd do a comparison between 480p and 240p on the GBP, but for now I can't. I do have a friend with a set, so I'll see if I can borrow them for a short while in the future.