Good thinking, but no, it doesn’t work.
Needless to say that I tried several things on the OSSC itself (messing with sync options, compatibility options and what not). I’ve changed some settings in the softmod menu itself as well, like “force PAL60” etc, so far no luck.
This is very weird. It was a good idea though, I haven’t think of the “480p dashboard trick” yet, too bad it doesn’t work.