system-config-display would let me configure dual-head setups. It doesn't look like I can do that in firstboot. Would be nice.
This will require some patches to s-c-display to provide a more complicated widget to firstboot. I can help on this and perhaps supply a patch in a bit, but I wanted to get it on the right project first.
Since this bugzilla report was filed, there have been several major updates in various components of the Xorg system, which may have resolved this issue. Users who have experienced this problem are encouraged to upgrade their system to the latest version of their packages (at least F12Beta, but even better if the very latest versions). Please, if you experience this problem on the up-to-date system, let us now in the comment for this bug, or whether the upgraded system works for you. If you won't be able to reply in one month, I will have to close this bug as INSUFFICIENT_DATA. Thank you. [This is a bulk message for all open Fedora Rawhide Xorg-related bugs. I'm adding myself to the CC list for each bug, so I'll see any comments you make after this and do my best to make sure every issue gets proper attention.]
Yeah, I think this is working now; thanks.