After Effects, Kona and video colour-space

Final Cut Pro is a proper video app that knows about video hardware. If you have a Kona card (or worse a Black Magic card!) then you ingest YUV data off tape and lay-back in the same way. The colour space is the same throughout the process and there is no colour space conversion.
See a previous entry here for details on TV colour space matrices.
Anyway - we're finishing a project at five and we discover they want to use a feature of the Kona card called Desktop Passthrough (or somesuch) which allows the SDi output to appear as a second GUI monitor. It is a feature specifically for those apps that don't know about video hardware but where having a preview on a video monitor would be useful. As far as After Effects is concerned the Kona card is a second Mac desktop monitor and you can send it's output full-screen to that display. My initial worry was that being an RGB-only program how would the Kona deal with the RGB feed? I imagined it did a quick and dirty transcode, probably not paying any attention to the 601 or 709 matrix (depending on standard or hi-def). We were pleasantly suprised when (after having calibrated the SDi monitor for correct colour in FCP) we found the probe telling us that the whites out of After Effects were bang-on!