Thank you, @dergigi! Really appreciate the feedback. Some responses to your thoughts/questions:

That's an interesting perspective on the semantics and connotation of "tips" that I'll have to think more about. You may be right that the distinction between that and "giving value back" is relevant. I did consider using other words like "boost" as well but ultimately landed on "tips" as I thought it required the least explanation. What Adam Curry and Co. have done with podcasting 2.0 is really great, I looked closely at the spec in the early days of designing Wavlake for inspiration.

You don't have to check for payment, the button is more of a fallback in case the user switches away from the front-end to pay and the page misses the update for some reason. I ran into this sometimes on mobile during development but am not sure exactly what causes the failure yet.

I'd love to integrate lnurl-auth! There's nothing really built yet for logged-in users so I moved it into the backlog until there's more of reason to login. When the time comes, though, I definitely will add Login with Lightning (and maybe some other lnurl elements, too, so much good stuff there). Love the design of that button, btw :)