eta: that change is somewhere in the neighborhood of horrifically wrong. You should've just fixed cdda_from_cdrom.
fixing cdda_from_cdrom requires changes in the way scsi works in drivers using that call (affecting among others gdrom.c and cubocd32.c). changes to scsi to pass a device in those two drivers might require a full device-ification of scsi, and hence touching the drivers using it (firebeat, ksys573 and dc among others)
I hope you realize it's not something I could have fixed in half an hour, like adding a tag in the interface. proper fix is in my (growing) todo list.
Given that I clearly documented the reason of the ghastly hack (so that the system will work in 0.135 but we know the fix is not good), I think we can live with it until I have some more spare time