Regardless of whether those IDs are still useful or not, does that mean that we should be dumping PS2 discs differently, given the principle that we should try and preserve everything contained on the disc?

If those IDs are only readable by the PS2 itself, are there any other bits of the disc that are similarly only readable by the PS2? Maybe we should be dumping PS2 discs with PS2 optical drives?

And out of interest, where exactly are these IDs stored on the disc, and how are they only readable by the PS2? Maybe it's possible (e.g. with hacked firmware) to read them on normal optical drives after all?