My understanding is that the thing that makes M-Disc DVDs special is that they don't use organic dyes in the recording. Blu-ray discs, with the exception of the weird LTH ones, by default don't use organic dyes. Consequently, the main magic of DVD M-Disc is just the default with BDR.

For a long time the vast majority of DVD-R disks have been light-to-dark (ie, the laser writing to a spot makes that spot darker, not lighter.) Dark-to-light disks were rare, the cheapest, and fell out of production pretty fast.

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