Yes, that might be helpful. If I understand you right, the official ROM on that page does probably not contain the incompatibility (yet)?
You can just reboot the device as usual from the power menu. The next version of Xposed Installer will use a custom build of BusyBox to reboot, so this error and also a problem with some HTC phones shouldn't happen anymore.
Maybe it just a bug which only cause on MI2/MI3, because many people who use them said xposed can't work on it, others seems not.
And I heard WSM is working on it...Anyway, here is the log.