Perhaps something like “Google CEO.*(?!head explodes)” Which would match if “Google CEO” isn’t at some point followed by “head explodes”

Gold Sponsor!

I hope so, although it might serve as an easy way for companies to bribe the first lady Musk for favours with Trump

Or run the raid 5 or 6 separately, with hardware raid or mdadm

Even for simple mirroring there’s an argument to be made for running it separately from btrfs using mdadm. You do lose the benefit of btrfs being able to automatically pick the valid copy on localised corruption, but the admin tools are easier to use and more proven in a case of full disk failure, and if you run an encrypted block device you need to encrypt half as much stuff.