LNURLw attempts to pay the invoices synchronously, waits for the payment to compete and only after that returns HTTP response. See api_lnurl_callback().
What results in a bad UX if a payment takes longer than http request timeout: the http calls times out, but then the payment arrives.
Such behavior does not conform LUD-03:
LN SERVICE sends a [...] JSON response and then attempts to pay the invoices asynchronously.
LNURLw attempts to pay the invoices synchronously, waits for the payment to compete and only after that returns HTTP response. See api_lnurl_callback().
What results in a bad UX if a payment takes longer than http request timeout: the http calls times out, but then the payment arrives.
Such behavior does not conform LUD-03: