Even in driver 14.4 I get the BSOD on RiftEnabler.sys.
The trick is to put the Rift into Direct Mode, then turn it OFF. Then change your Crossfire settings. You do sometimes get the BSOD again, but providing when you reboot your Rift is still off, you can then change the setting.
After that, set everything back to how it needs to be for Elite (Extended mode).
Bit of a faff, but it works.
Ah ok I'll remember to do that, thanks very much.