ahh the amiga, possibly the biggest downer i had using the ossc, though not a disaster.
i use a samsung tv with scart all hooked up in x2 and is fine, though apart from slight colour improvement i see no difference at all from scart to tv. it is working with x5 but the image is stretched and distorted.
using 3.1 workbench and 3.0 roms monitor types are limited.. also only have pal high res, pal high res interlace and ntsc with interlace. through the ossc it does no deinterlacing at all, passthrough mode as well .. odd. with scart straight to tv i get nice deinterlacing.
my only hunch is the monitor types and the drivers for these.