@paulcuth some ux suggestions:

1. maybe add the @ prefix if someone forgets or let people paste in their profile urls. more work for you, but makes reduces form errors.

2. perhaps link to the front page or some kind of blurb of what this is on the profile pages, as someone might arrive there from a link and not realize they can plug in their profile and see what's there (kind of feels like a linktree the way it is) https://rss-is-dead.lol/user?profileUrl=https%3A%2F%2Fmastodon.online%2Fusers%2Frosano