Quite handy for doing the annoying bits of this yourself. I don't really like the private key being just available but I also don't have a solution for generating this that doesn't include private keys but is also generally useful.
Yeah, you have a point. For security, implementation goes like this: the keys are generated once for a page load and are not recorded (for obvious reason - security), keys are gone after closing the browser tab, so, as far as tool is concerned keys are ephemeral. To generate new keys simply reload the page.
Can it be extended to Rosenpass?
That's an interesting project, perhaps one day, if so I'll post Show HN again :)