@lars.haglund, this is an interesting point and quite frankly, I’m not exactly certain. I never really was a fan of supplying the DCDM output transforms as I knew they could create confusion with images mastered using one of the P3 variants. If I wanted to guarantee the exact appearance of my master using the P3 output transform, I would use a third-party conversion tool to create the X’Y’Z’ encoded DCDM files from the P3 files, rather than switching the ODT. In theory it should work, but I’m not certain if it does as there are a number of inconsistencies that I am hoping we clean up with ACES 2.0. (The scaling and roll-off step is one of them - it exists for a specific reason but is not easily extensible to other transforms nor documented well.)
Note this statement from the TB that you mention:
It is not recommended to use the DCDM ODT during the DI process. Rather, the DCDM ODT is provided as a convenience to aid in the conversion of the final RGB graded master into a DCDM version when more appropriate tools are not available. In general, it is recommended that RGB master files be produced with the appropriate ODT for the mastering display device and that those RGB files be converted to a DCDM using a tool designed for DCDM transcodings.
For your questions:
This draft document was never officially published, but you can find it here:
TB_2018_002_v0.2.pdf (256.7 KB) (file last updated 08/06/2018)
(from this thread Request for review and comments on v0.1 Draft of "ACES Output Transform Details")
These are just theoretical values that were run through the transforms and the expected colorimetry on screen, assuming proper calibration and . No EXRs were created (although they could be) - it was expected that they could be made trivially in an RGB generator in a color corrector or other software driving the projector image. I can make these for you if it would be helpful.
The test values listed for each transform were generated by running the ACES values through the transforms and calculating what the screen colorimetry would be. So yes, the scale factors are taken into account for the xyY values listed in that table.