There is some surprising behavior with some of the features of yaml, mostly arising from the fact that it looks nice to read. Here’s a list of things that you can avoid to avoid a lot of the pitfalls: https://hitchdev.com/strictyaml/why/ . I haven’t actually used strictyaml, but the arguments it presents are pretty solid and some are things I’ve run into in real environments
For anyone else trying to get it to work on firefox, it doesn’t support passkeys yet but it’s on the roadmap. https://connect.mozilla.org/t5/ideas/support-webauthn-passkeys/idc-p/30123/highlight/true#M17028
tailscale also just has a button to buy/enable mullvad as an exit node. if you’re just looking for a commercial vpn for privacy it works well.