Thank you for sharing these sign up options, they both look interesting. the dropdown is useful is the system is able to detect information from the user device and display the latest/common one.

A good way to start nostr onboarding is nstart.me that provide a guided tour and explanation on the different options.

Don't remember it mentioning the extension, from what I know, it only works from desktop, as only few (chromium based third-party) mobile browsers currently support browser extensions.