I haven't heard of a beta, I'm afraid, but I need to get the camera working much earlier than New Year. I've paid over 1.1k GBP for the X that is now crippled and forces me to take a separate camera with me at all times (it sounds even more ridiculous when I write it down).
If you save your data on iCloud or via iTunes on your Mac or Windows computer, you will only have a backup of the current iOS version you are on. I had to learn it the hard way myself - I made a backup before upgrading to 11.2 and restored from that backup after the upgrade. Later on when I noticed the issues with 11.2 I downgraded to 11.1.2 and wanted to restore from my former 11.1.2 backup but iTunes didn't show this older backup anymore. What it did was overwriting the backup with the 11.2 data immediately after I had upgraded which made it impossible to get my data back onto my phone on a lower firmware. The only "solution" was to upgrade again to 11.2, restore from the backup and crippling my camera again.
That's the current status quo, the only thing I can do now is sit and wait until Apple releases a fix (or go back to 11.1.2 and loose all my data).
If you want to save a backup permanently, you need to archive it in iTunes' preferences (another ridiculous way to hide this option, why can't you do that directly in iTunes frontend?). Unfortunately, I only learned about that when it was already too late for me.