Yes, I've created MPEG2 in Compressor and then sent it to Toast for authoring a Blu-ray. Toast did not re-encode, but when it muxes the video and audio together, it results in a blocky, skipping unusable video stream.
I've also been able to edit P2 footage@ 720p, 59.94 and export from FCP as Quciktime using current settings, then have Toast encode & author to Blu-Ray successfully. But there is just no way to use Compressor to encode anything for Blu-Ray that Toast can use successfully without re-encoding. I would love for somebody to prove me wrong, though.