Pending payments are a common UX problem for LN that users often complain about. While the cause of this problem is not easily unraveled, there have been several issues involving stuck intermediate nodes awaiting revocation and recipients who can’t give timely preimage replies.

Fabrice Drouin proposed a change to address the issue using a faster “proceed/try another route” answer using a probe with a short timeout requirement. The system sends the blank probe request prior to sending the actual payment, via the same route.