Harmy said:

I'm still having some trouble getting my computer to use the BD footage properly though, so it would be quite nice to get the scene already brightened and corrected in high bitrate 720p AVC.

Have you tried demuxing the video track from the blu-ray m2ts file? It worked for me in after effects after demuxing it to ".h264" and changing that extension to just ".264".

Anyway, I'll try and make a render someday soon. The original in 1080p is 36,8 mbps, so what would be the best bitrate to use for 720p?