Comment 8 for bug 2054127

Currently MAAS relies on exiting GRUB when booting a 3rd party operating system that isn't currently bootable via the Canonical shim. We do plan on fixing this by allowing shim chainloading, but currently exit is required for MAAS.

After that it would be possible to get rid of exit, and from a security engineering perspective it would be nice as it would avoid all the resource deallocation paths, but as a user it would annoy me a little bit, so I am not entirely sure what is the right choice.