Genuinely curious: do programs read bodies of 429 responses? In the code bases that I have seen, 429 is not read beyond the code itself
If I find something useful there, I'll read it and code for it...
Almost certainly not by default, certainly not in any of the http libs I have used
Sometimes! The server can also send a retry-after header to indicate when the client is allowed to request the resource again: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/...