I have tried btrfs in the past and when it goes wrong you are utterly shafted. You can’t even mount it as a read only file system, it will just lock you out entirely. And the support isn’t great, I ended up finding something that had a disclaimer along the lines of “only run this if you really know what you’re doing”, but obviously I didn’t as the documentation didn’t tell me enough to know. So the only people who could possibly know are the developers of the file system themselves. Anyway, I was 2 days in to trying to recover my data by this point so I gave it a go, nothing to lose - it refused to do anything. Great.

So in summary I’m not going to try it again.