External SuperDrive woes

I have a MacBook Pro (“Retina, 15-inch, Early 2013”). I also have an external SuperDrive, revision¬†2.00 according to drutil. At some point, the MacBook Pro decided that the SuperDrive is “Unsupported”, according to drutil. Lots of people report similar problems. They advise setting a boot-args parameter, mbasd=1, in the NVRAM (by executing nvram boot-args="mbasd=1").

Unfortunately, in order to set boot arguments nowadays one must disable System Integrity Protection by booting into Recovery mode. Armed with such dangerous knowledge, I booted into Recovery mode and disabled System Integrity Protection with csrutil disable, intending to then set boot-args to mbasd=1. However, upon reboot the SuperDrive started working before I changed the boot arguments, so I copied the CD I needed to and went back and re-enabled System Integrity Protection with csrutil enable and rebooted without bothering to modify the NVRAM boot-args parameter. The drive worked briefly after that and went back to the old behavior.

Apparently it doesn’t need the mbasd=1 parameter in order to see the drive. Maybe it does in order to continue seeing it. I have no idea why this is the case. I’m just documenting it for the next person trying to figure this out.

Update, May 19, 2017:

Well, it stopped working again, so I went through the whole dance of going to System Recovery Mode, disabling System Integrity Protection, setting the boot flag, going into System Recovery Mode again, and enabling System Integrity Protection. It seems to work fine now across reboots. I have no idea why, but you should probably just do the same thing.

Update, June 20, 2017:

It stopped working yet again. The boot-args flag is still set, so I have no idea why. I had to reboot into System Recovery Mode in order to read a disc.